Re: Display class

Re: Display class

[Miguel Ojeda Sandonis]

Ok, here is the patch (against git7+displayclass) which moves auxdisplay/*
to video/display/* and start using the display class.

It is just a draft, but there isn't much code changed from -mm2.

  - I would remove "struct device *dev, void *devdata" of display_device_register()
    Are they neccesary for other display drivers? I have to pass NULL right now.

  - I would add a paramtere ("char *name") to display_device_register() so we
    set the name when registering. Right now I have to set my name after inited,
    and this is a Linux module and not a person borning, right? ;)

  - I would add a read/writeable attr called "rate" for set/unset the refresh rate
    of a display.

  - I was going to maintain the drivers/auxdisplay/* tree.
    Are you going to maintain the driver? I think so, just for being sure.

P.S.

  When I was working at 2.6.19-rc6-mm2 it worked all fine, but now
  I have copied it to git7 I'm getting some weird segmentation faults
  (oops) when at cfag12864bfb_init, at mutex_lock() in
  display_device_unregister module... I think unrelated (?), but I will
  look for some mistake I made.

miguelojeda-draft-drivers-video-display-add-support.patch
Signed-off-by: Miguel Ojeda Sandonis <maxextreme@gmail.com>
---
diff --git a/CREDITS b/CREDITS
index d088008..b55312a 100644
--- a/CREDITS
+++ b/CREDITS
@@ -2562,6 +2562,16 @@ S: Subiaco, 6008
 S: Perth, Western Australia
 S: Australia
 
+N: Miguel Ojeda Sandonis
+E: maxextreme@gmail.com
+W: http://maxextreme.googlepages.com/
+D: Author: ks0108 LCD Controller driver
+D: Author: cfag12864b LCD driver
+D: Author: cfag12864bfb LCD framebuffer driver
+S: C/ Mieses 20, 9-B
+S: Valladolid 47009
+S: Spain
+
 N: Greg Page
 E: gpage@sovereign.org
 D: IPX development and support
diff --git a/Documentation/display/cfag12864b b/Documentation/display/cfag12864b
new file mode 100644
index 0000000..8b6c01d
--- /dev/null
+++ b/Documentation/display/cfag12864b
@@ -0,0 +1,105 @@
+	===================================
+	cfag12864b LCD Driver Documentation
+	===================================
+
+License:		GPLv2
+Author & Maintainer:	Miguel Ojeda Sandonis <maxextreme@gmail.com>
+Date:			2006-10-31
+
+
+
+--------
+0. INDEX
+--------
+
+	1. DRIVER INFORMATION
+	2. DEVICE INFORMATION
+	3. WIRING
+	4. USERSPACE PROGRAMMING
+
+
+---------------------
+1. DRIVER INFORMATION
+---------------------
+
+This driver support one cfag12864b display at time.
+
+
+---------------------
+2. DEVICE INFORMATION
+---------------------
+
+Manufacturer:	Crystalfontz
+Device Name:	Crystalfontz 12864b LCD Series
+Device Code:	cfag12864b
+Webpage:	http://www.crystalfontz.com
+Device Webpage:	http://www.crystalfontz.com/products/12864b/
+Type:		LCD (Liquid Crystal Display)
+Width:		128
+Height:		64
+Colors:		2 (B/N)
+Controller:	ks0108
+Controllers:	2
+Pages:		8 each controller
+Addresses:	64 each page
+Data size:	1 byte each address
+Memory size:	2 * 8 * 64 * 1 = 1024 bytes = 1 Kbyte
+
+
+---------
+3. WIRING
+---------
+
+The cfag12864b LCD Series don't have official wiring.
+
+The common wiring is done to the parallel port as shown:
+
+Parallel Port                          cfag12864b
+
+  Name Pin#                            Pin# Name
+
+Strobe ( 1)------------------------------(17) Enable
+Data 0 ( 2)------------------------------( 4) Data 0
+Data 1 ( 3)------------------------------( 5) Data 1
+Data 2 ( 4)------------------------------( 6) Data 2
+Data 3 ( 5)------------------------------( 7) Data 3
+Data 4 ( 6)------------------------------( 8) Data 4
+Data 5 ( 7)------------------------------( 9) Data 5
+Data 6 ( 8)------------------------------(10) Data 6
+Data 7 ( 9)------------------------------(11) Data 7
+       (10)                      [+5v]---( 1) Vdd
+       (11)                      [GND]---( 2) Ground
+       (12)                      [+5v]---(14) Reset
+       (13)                      [GND]---(15) Read / Write
+  Line (14)------------------------------(13) Controller Select 1
+       (15)
+  Init (16)------------------------------(12) Controller Select 2
+Select (17)------------------------------(16) Data / Instruction
+Ground (18)---[GND]              [+5v]---(19) LED +
+Ground (19)---[GND]
+Ground (20)---[GND]              E    A             Values:
+Ground (21)---[GND]       [GND]---[P1]---(18) Vee    · R = Resistor = 22 ohm
+Ground (22)---[GND]                |                 · P1 = Preset = 10 Kohm
+Ground (23)---[GND]       ----   S ------( 3) V0     · P2 = Preset = 1 Kohm
+Ground (24)---[GND]       |  |
+Ground (25)---[GND] [GND]---[P2]---[R]---(20) LED -
+
+
+------------------------
+4. USERSPACE PROGRAMMING
+------------------------
+
+The cfag12864bfb describes a framebuffer device (/dev/fbX).
+
+It has a size of 1024 bytes = 1 Kbyte.
+Each bit represents one pixel. If the bit is high, the pixel will
+turn on. If the pixel is low, the pixel will turn off.
+
+You can use the framebuffer as a file: fopen, fwrite, fclose...
+Although the LCD won't get updated until the next refresh time arrives.
+
+Also, you can mmap the framebuffer: open & mmap, munmap & close...
+which is the best option for most uses.
+
+Check Documentation/auxdisplay/cfag12864b-example.c
+for a real working userspace complete program with usage examples.
diff --git a/Documentation/display/cfag12864b-example.c b/Documentation/display/cfag12864b-example.c
new file mode 100644
index 0000000..7bfac35
--- /dev/null
+++ b/Documentation/display/cfag12864b-example.c
@@ -0,0 +1,282 @@
+/*
+ *    Filename: cfag12864b-example.c
+ *     Version: 0.1.0
+ * Description: cfag12864b LCD userspace example program
+ *     License: GPLv2
+ *
+ *      Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
+ *        Date: 2006-10-31
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+/*
+ * ------------------------
+ * start of cfag12864b code
+ * ------------------------
+ */
+
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+
+#define CFAG12864B_WIDTH		(128)
+#define CFAG12864B_HEIGHT		(64)
+#define CFAG12864B_SIZE			(128 * 64 / 8)
+#define CFAG12864B_BPB			(8)
+#define CFAG12864B_ADDRESS(x, y)	((y) * CFAG12864B_WIDTH / \
+					CFAG12864B_BPB + (x) / CFAG12864B_BPB)
+#define CFAG12864B_BIT(n)		(((unsigned char) 1) << (n))
+
+#undef CFAG12864B_DOCHECK
+#ifdef CFAG12864B_DOCHECK
+	#define CFAG12864B_CHECK(x, y)		((x) < CFAG12864B_WIDTH && \
+						(y) < CFAG12864B_HEIGHT)
+#else
+	#define CFAG12864B_CHECK(x, y)		(1)
+#endif
+
+int cfag12864b_fd;
+unsigned char * cfag12864b_mem;
+unsigned char cfag12864b_buffer[CFAG12864B_SIZE];
+
+/*
+ * init a cfag12864b framebuffer device
+ *
+ * No error:       return = 0
+ * Unable to open: return = -1
+ * Unable to mmap: return = -2
+ */
+int cfag12864b_init(char *path)
+{
+	cfag12864b_fd = open(path, O_RDWR);
+	if (cfag12864b_fd == -1)
+		return -1;
+
+	cfag12864b_mem = mmap(0, CFAG12864B_SIZE, PROT_READ | PROT_WRITE,
+		MAP_SHARED, cfag12864b_fd, 0);
+	if (cfag12864b_mem == MAP_FAILED) {
+		close(cfag12864b_fd);
+		return -2;
+	}
+
+	return 0;
+}
+
+/*
+ * exit a cfag12864b framebuffer device
+ */
+void cfag12864b_exit(void)
+{
+	munmap(cfag12864b_mem, CFAG12864B_SIZE);
+	close(cfag12864b_fd);
+}
+
+/*
+ * set (x, y) pixel
+ */
+void cfag12864b_set(unsigned char x, unsigned char y)
+{
+	if (CFAG12864B_CHECK(x, y))
+		cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] |=
+			CFAG12864B_BIT(x % CFAG12864B_BPB);
+}
+
+/*
+ * unset (x, y) pixel
+ */
+void cfag12864b_unset(unsigned char x, unsigned char y)
+{
+	if (CFAG12864B_CHECK(x, y))
+		cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] &=
+			~CFAG12864B_BIT(x % CFAG12864B_BPB);
+}
+
+/*
+ * is set (x, y) pixel?
+ *
+ * Pixel off: return = 0
+ * Pixel on:  return = 1
+ */
+unsigned char cfag12864b_isset(unsigned char x, unsigned char y)
+{
+	if (CFAG12864B_CHECK(x, y))
+		if (cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] &
+			CFAG12864B_BIT(x % CFAG12864B_BPB))
+			return 1;
+
+	return 0;
+}
+
+/*
+ * not (x, y) pixel
+ */
+void cfag12864b_not(unsigned char x, unsigned char y)
+{
+	if (cfag12864b_isset(x, y))
+		cfag12864b_unset(x, y);
+	else
+		cfag12864b_set(x, y);
+}
+
+/*
+ * fill (set all pixels)
+ */
+void cfag12864b_fill(void)
+{
+	unsigned short i;
+
+	for (i = 0; i < CFAG12864B_SIZE; i++)
+		cfag12864b_buffer[i] = 0xFF;
+}
+
+/*
+ * clear (unset all pixels)
+ */
+void cfag12864b_clear(void)
+{
+	unsigned short i;
+
+	for (i = 0; i < CFAG12864B_SIZE; i++)
+		cfag12864b_buffer[i] = 0;
+}
+
+/*
+ * format a [128*64] matrix
+ *
+ * Pixel off: src[i] = 0
+ * Pixel on:  src[i] > 0
+ */
+void cfag12864b_format(unsigned char * matrix)
+{
+	unsigned char i, j, n;
+
+	for (i = 0; i < CFAG12864B_HEIGHT; i++)
+	for (j = 0; j < CFAG12864B_WIDTH / CFAG12864B_BPB; j++) {
+		cfag12864b_buffer[i * CFAG12864B_WIDTH / CFAG12864B_BPB +
+			j] = 0;
+		for (n = 0; n < CFAG12864B_BPB; n++)
+			if (matrix[i * CFAG12864B_WIDTH +
+				j * CFAG12864B_BPB + n])
+				cfag12864b_buffer[i * CFAG12864B_WIDTH /
+					CFAG12864B_BPB + j] |=
+					CFAG12864B_BIT(n);
+	}
+}
+
+/*
+ * blit buffer to lcd
+ */
+void cfag12864b_blit(void)
+{
+	memcpy(cfag12864b_mem, cfag12864b_buffer, CFAG12864B_SIZE);
+}
+
+/*
+ * ----------------------
+ * end of cfag12864b code
+ * ----------------------
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#define EXAMPLES	6
+
+void example(unsigned char n)
+{
+	unsigned short i, j;
+	unsigned char matrix[CFAG12864B_WIDTH * CFAG12864B_HEIGHT];
+
+	if (n > EXAMPLES)
+		return;
+
+	printf("Example %i/%i - ", n, EXAMPLES);
+
+	switch (n) {
+	case 1:
+		printf("Draw points setting bits");
+		cfag12864b_clear();
+		for (i = 0; i < CFAG12864B_WIDTH; i += 2)
+			for (j = 0; j < CFAG12864B_HEIGHT; j += 2)
+				cfag12864b_set(i, j);
+		break;
+
+	case 2:
+		printf("Clear the LCD");
+		cfag12864b_clear();
+		break;
+
+	case 3:
+		printf("Draw rows formatting a [128*64] matrix");
+		memset(matrix, 0, CFAG12864B_WIDTH * CFAG12864B_HEIGHT);
+		for (i = 0; i < CFAG12864B_WIDTH; i++)
+			for (j = 0; j < CFAG12864B_HEIGHT; j += 2)
+				matrix[j * CFAG12864B_WIDTH + i] = 1;
+		cfag12864b_format(matrix);
+		break;
+
+	case 4:
+		printf("Fill the lcd");
+		cfag12864b_fill();
+		break;
+
+	case 5:
+		printf("Draw columns unsetting bits");
+		for (i = 0; i < CFAG12864B_WIDTH; i += 2)
+			for (j = 0; j < CFAG12864B_HEIGHT; j++)
+				cfag12864b_unset(i, j);
+		break;
+
+	case 6:
+		printf("Do negative not-ing all bits");
+		for (i = 0; i < CFAG12864B_WIDTH; i++)
+			for (j = 0; j < CFAG12864B_HEIGHT; j ++)
+				cfag12864b_not(i, j);
+		break;
+	}
+
+	puts(" - [Press Enter]");
+}
+
+int main(int argc, char *argv[])
+{
+	unsigned char n;
+
+	if (argc != 2) {
+		printf(
+			"Sintax:  %s fbdev\n"
+			"Usually: /dev/fb0, /dev/fb1...\n", argv[0]);
+		return -1;
+	}
+
+	if (cfag12864b_init(argv[1])) {
+		printf("Can't init %s fbdev\n", argv[1]);
+		return -2;
+	}
+
+	for (n = 1; n <= EXAMPLES; n++) {
+		example(n);
+		cfag12864b_blit();
+		while (getchar() != '\n');
+	}
+
+	cfag12864b_exit();
+
+	return 0;
+}
diff --git a/Documentation/display/ks0108 b/Documentation/display/ks0108
new file mode 100644
index 0000000..a006f79
--- /dev/null
+++ b/Documentation/display/ks0108
@@ -0,0 +1,55 @@
+	==========================================
+	ks0108 LCD Controller Driver Documentation
+	==========================================
+
+License:		GPLv2
+Author & Maintainer:	Miguel Ojeda Sandonis <maxextreme@gmail.com>
+Date:			2006-10-31
+
+
+
+--------
+0. INDEX
+--------
+
+	1. DRIVER INFORMATION
+	2. DEVICE INFORMATION
+	3. WIRING
+
+
+---------------------
+1. DRIVER INFORMATION
+---------------------
+
+This driver support the ks0108 LCD controller.
+
+
+---------------------
+2. DEVICE INFORMATION
+---------------------
+
+Manufacturer:	Samsung
+Device Name:	KS0108 LCD Controller
+Device Code:	ks0108
+Webpage:	-
+Device Webpage:	-
+Type:		LCD Controller (Liquid Crystal Display Controller)
+Width:		64
+Height:		64
+Colors:		2 (B/N)
+Pages:		8
+Addresses:	64 each page
+Data size:	1 byte each address
+Memory size:	8 * 64 * 1 = 512 bytes
+
+
+---------
+3. WIRING
+---------
+
+The driver supports data parallel port wiring.
+
+If you aren't building LCD related hardware, you should check
+your LCD specific wiring information in the same folder.
+
+For example, check Documentation/display/cfag12864b.
diff --git a/MAINTAINERS b/MAINTAINERS
index 5dff268..e31e0bf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -659,6 +659,20 @@ L:	linux-kernel@vger.kernel.org
 L:	discuss@x86-64.org
 S:	Maintained
 
+CFAG12864B LCD DRIVER
+P:	Miguel Ojeda Sandonis
+M:	maxextreme@gmail.com
+W:	http://maxextreme.googlepages.com/display.htm
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+
+CFAG12864BFB LCD FRAMEBUFFER DRIVER
+P:	Miguel Ojeda Sandonis
+M:	maxextreme@gmail.com
+W:	http://maxextreme.googlepages.com/display.htm
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+
 COMMON INTERNET FILE SYSTEM (CIFS)
 P:	Steve French
 M:	sfrench@samba.org
@@ -1752,6 +1766,13 @@ M:	davem@davemloft.net
 L:	linux-kernel@vger.kernel.org
 S:	Maintained
 
+KS0108 LCD CONTROLLER DRIVER
+P:	Miguel Ojeda Sandonis
+M:	maxextreme@gmail.com
+W:	http://maxextreme.googlepages.com/display.htm
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+
 LAPB module
 L:	linux-x25@vger.kernel.org
 S:	Orphan
diff --git a/drivers/video/display/Kconfig b/drivers/video/display/Kconfig
index db2dae4..0c655a5 100644
--- a/drivers/video/display/Kconfig
+++ b/drivers/video/display/Kconfig
@@ -26,4 +26,102 @@ config DISPLAY_DDC
 comment "Display hardware drivers"
 	depends on DISPLAY_SUPPORT
 
+config KS0108
+	tristate "KS0108 LCD Controller"
+	depends on PARPORT_PC
+	depends on DISPLAY_SUPPORT
+	default n
+	---help---
+	  If you have a LCD controlled by one or more KS0108
+	  controllers, say Y. You will need also another more specific
+	  driver for your LCD.
+
+	  Depends on Parallel Port support. If you say Y at
+	  parport, you will be able to compile this as a module (M)
+	  and built-in as well (Y).
+
+	  To compile this as a module, choose M here:
+	  the module will be called ks0108.
+
+	  If unsure, say N.
+
+config KS0108_PORT
+	hex "Parallel port where the LCD is connected"
+	depends on KS0108
+	default 0x378
+	---help---
+	  The address of the parallel port where the LCD is connected.
+
+	  The first  standard parallel port address is 0x378.
+	  The second standard parallel port address is 0x278.
+	  The third  standard parallel port address is 0x3BC.
+
+	  You can specify a different address if you need.
+
+	  If you don't know what I'm talking about, load the parport module,
+	  and execute "dmesg" or "cat /proc/ioports". You can see there how
+	  many parallel ports are present and which address each one has.
+
+	  Usually you only need to use 0x378.
+
+	  If you compile this as a module, you can still override this
+	  using the module parameters.
+
+config KS0108_DELAY
+	int "Delay between each control writing (microseconds)"
+	depends on KS0108
+	default "2"
+	---help---
+	  Amount of time the ks0108 should wait between each control write
+	  to the parallel port.
+
+	  If your driver seems to miss random writings, increment this.
+
+	  If you don't know what I'm talking about, ignore it.
+
+	  If you compile this as a module, you can still override this
+	  value using the module parameters.
+
+config CFAG12864B
+	tristate "CFAG12864B LCD"
+	depends on X86
+	depends on KS0108
+	default n
+	---help---
+	  If you have a Crystalfontz 128x64 2-color LCD, cfag12864b Series,
+	  say Y. You also need the ks0108 LCD Controller driver.
+
+	  For help about how to wire your LCD to the parallel port,
+	  check Documentation/auxdisplay/cfag12864b
+
+	  The LCD framebuffer driver can be attached to a console.
+	  It will work fine. However, you can't attach it to the fbdev driver
+	  of the xorg server.
+
+	  To compile this as a module, choose M here:
+	  the modules will be called cfag12864b and cfag12864bfb.
+
+	  If unsure, say N.
+
+config CFAG12864B_RATE
+	int "Refresh rate (hertzs)"
+	depends on CFAG12864B
+	default "20"
+	---help---
+	  Refresh rate of the LCD.
+
+	  As the LCD is not memory mapped, the driver has to make the work by
+	  software. This means you should be careful setting this value higher.
+	  If your CPUs are really slow or you feel the system is slowed down,
+	  decrease the value.
+
+	  Be careful modifying this value to a very high value:
+	  You can freeze the computer, or the LCD maybe can't draw as fast as you
+	  are requesting.
+
+	  If you don't know what I'm talking about, ignore it.
+
+	  If you compile this as a module, you can still override this
+	  value using the module parameters.
+
 endmenu
diff --git a/drivers/video/display/Makefile b/drivers/video/display/Makefile
index d210f52..fc9f7dd 100644
--- a/drivers/video/display/Makefile
+++ b/drivers/video/display/Makefile
@@ -5,3 +5,6 @@ display-objs				:= display-sysfs.o 
 obj-$(CONFIG_DISPLAY_SUPPORT)		+= display.o
 
 obj-$(CONFIG_DISPLAY_DDC)		+= display-ddc.o
+
+obj-$(CONFIG_KS0108)			+= ks0108.o
+obj-$(CONFIG_CFAG12864B)		+= cfag12864b.o cfag12864bfb.o
diff --git a/drivers/video/display/cfag12864b.c b/drivers/video/display/cfag12864b.c
new file mode 100644
index 0000000..1a25df9
--- /dev/null
+++ b/drivers/video/display/cfag12864b.c
@@ -0,0 +1,404 @@
+/*
+ *    Filename: cfag12864b.c
+ *     Version: 0.1.0
+ * Description: cfag12864b LCD driver
+ *     License: GPLv2
+ *     Depends: ks0108
+ *
+ *      Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
+ *        Date: 2006-10-31
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/jiffies.h>
+#include <linux/mutex.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+#include <linux/workqueue.h>
+#include <linux/ks0108.h>
+#include <linux/cfag12864b.h>
+
+
+#define CFAG12864B_NAME "cfag12864b"
+
+/*
+ * Module Parameters
+ */
+
+static unsigned int cfag12864b_rate = CONFIG_CFAG12864B_RATE;
+module_param(cfag12864b_rate, uint, S_IRUGO);
+MODULE_PARM_DESC(cfag12864b_rate,
+	"Refresh rate (hertzs)");
+
+unsigned int cfag12864b_get_rate(void)
+{
+	return cfag12864b_rate;
+}
+
+/*
+ * cfag12864b Commands
+ *
+ *	E = Enable signal
+ *		Everytime E switch from low to high,
+ *		cfag12864b/ks0108 reads the command/data.
+ *
+ *	CS1 = First ks0108controller.
+ *		If high, the first ks0108 controller receives commands/data.
+ *
+ *	CS2 = Second ks0108 controller
+ *		If high, the second ks0108 controller receives commands/data.
+ *
+ *	DI = Data/Instruction
+ *		If low, cfag12864b will expect commands.
+ *		If high, cfag12864b will expect data.
+ *
+ */
+
+#define bit(n) (((unsigned char)1)<<(n))
+
+#define CFAG12864B_BIT_E	(0)
+#define CFAG12864B_BIT_CS1	(2)
+#define CFAG12864B_BIT_CS2	(1)
+#define CFAG12864B_BIT_DI	(3)
+
+static unsigned char cfag12864b_state;
+
+static void cfag12864b_set(void)
+{
+	ks0108_writecontrol(cfag12864b_state);
+}
+
+static void cfag12864b_setbit(unsigned char state, unsigned char n)
+{
+	if (state)
+		cfag12864b_state |= bit(n);
+	else
+		cfag12864b_state &= ~bit(n);
+}
+
+static void cfag12864b_e(unsigned char state)
+{
+	cfag12864b_setbit(state, CFAG12864B_BIT_E);
+	cfag12864b_set();
+}
+
+static void cfag12864b_cs1(unsigned char state)
+{
+	cfag12864b_setbit(state, CFAG12864B_BIT_CS1);
+}
+
+static void cfag12864b_cs2(unsigned char state)
+{
+	cfag12864b_setbit(state, CFAG12864B_BIT_CS2);
+}
+
+static void cfag12864b_di(unsigned char state)
+{
+	cfag12864b_setbit(state, CFAG12864B_BIT_DI);
+}
+
+static void cfag12864b_setcontrollers(unsigned char first,
+	unsigned char second)
+{
+	if (first)
+		cfag12864b_cs1(0);
+	else
+		cfag12864b_cs1(1);
+
+	if (second)
+		cfag12864b_cs2(0);
+	else
+		cfag12864b_cs2(1);
+}
+
+static void cfag12864b_controller(unsigned char which)
+{
+	if (which == 0)
+		cfag12864b_setcontrollers(1, 0);
+	else if (which == 1)
+		cfag12864b_setcontrollers(0, 1);
+}
+
+static void cfag12864b_displaystate(unsigned char state)
+{
+	cfag12864b_di(0);
+	cfag12864b_e(1);
+	ks0108_displaystate(state);
+	cfag12864b_e(0);
+}
+
+static void cfag12864b_address(unsigned char address)
+{
+	cfag12864b_di(0);
+	cfag12864b_e(1);
+	ks0108_address(address);
+	cfag12864b_e(0);
+}
+
+static void cfag12864b_page(unsigned char page)
+{
+	cfag12864b_di(0);
+	cfag12864b_e(1);
+	ks0108_page(page);
+	cfag12864b_e(0);
+}
+
+static void cfag12864b_startline(unsigned char startline)
+{
+	cfag12864b_di(0);
+	cfag12864b_e(1);
+	ks0108_startline(startline);
+	cfag12864b_e(0);
+}
+
+static void cfag12864b_writebyte(unsigned char byte)
+{
+	cfag12864b_di(1);
+	cfag12864b_e(1);
+	ks0108_writedata(byte);
+	cfag12864b_e(0);
+}
+
+static void cfag12864b_nop(void)
+{
+	cfag12864b_startline(0);
+}
+
+/*
+ * cfag12864b Internal Commands
+ */
+
+static void cfag12864b_on(void)
+{
+	cfag12864b_setcontrollers(1, 1);
+	cfag12864b_displaystate(1);
+}
+
+static void cfag12864b_off(void)
+{
+	cfag12864b_setcontrollers(1, 1);
+	cfag12864b_displaystate(0);
+}
+
+static void cfag12864b_clear(void)
+{
+	unsigned char i, j;
+
+	cfag12864b_setcontrollers(1, 1);
+	for (i = 0; i < CFAG12864B_PAGES; i++) {
+		cfag12864b_page(i);
+		cfag12864b_address(0);
+		for (j = 0; j < CFAG12864B_ADDRESSES; j++)
+			cfag12864b_writebyte(0);
+	}
+}
+
+/*
+ * Update work
+ */
+
+unsigned char *cfag12864b_buffer;
+static unsigned char *cfag12864b_cache;
+static DEFINE_MUTEX(cfag12864b_mutex);
+static unsigned char cfag12864b_updating;
+static void cfag12864b_update(void *arg);
+static struct workqueue_struct *cfag12864b_workqueue;
+static DECLARE_WORK(cfag12864b_work, cfag12864b_update, NULL);
+
+static void cfag12864b_queue(void)
+{
+	queue_delayed_work(cfag12864b_workqueue, &cfag12864b_work,
+		HZ / cfag12864b_rate);
+}
+
+void cfag12864b_power_on(void)
+{
+	mutex_lock(&cfag12864b_mutex);
+
+	cfag12864b_on();
+
+	mutex_unlock(&cfag12864b_mutex);
+}
+
+void cfag12864b_power_off(void)
+{
+	mutex_lock(&cfag12864b_mutex);
+
+	cfag12864b_off();
+
+	mutex_unlock(&cfag12864b_mutex);
+}
+
+unsigned char cfag12864b_enable(void)
+{
+	unsigned char ret;
+
+	mutex_lock(&cfag12864b_mutex);
+
+	if (!cfag12864b_updating) {
+		cfag12864b_updating = 1;
+		cfag12864b_queue();
+		ret = 0;
+	} else
+		ret = 1;
+
+	mutex_unlock(&cfag12864b_mutex);
+
+	return ret;
+}
+
+void cfag12864b_disable(void)
+{
+	mutex_lock(&cfag12864b_mutex);
+
+	if (cfag12864b_updating) {
+		cfag12864b_updating = 0;
+		cancel_delayed_work(&cfag12864b_work);
+		flush_workqueue(cfag12864b_workqueue);
+		cfag12864b_off();
+	}
+
+	mutex_unlock(&cfag12864b_mutex);
+}
+
+unsigned char cfag12864b_is_enabled(void)
+{
+	return cfag12864b_updating;
+}
+
+static void cfag12864b_update(void *arg)
+{
+	unsigned char c;
+	unsigned short i, j, k, b;
+
+	if (memcmp(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE)) {
+		for (i = 0; i < CFAG12864B_CONTROLLERS; i++) {
+			cfag12864b_controller(i);
+			cfag12864b_nop();
+			for (j = 0; j < CFAG12864B_PAGES; j++) {
+				cfag12864b_page(j);
+				cfag12864b_nop();
+				cfag12864b_address(0);
+				cfag12864b_nop();
+				for (k = 0; k < CFAG12864B_ADDRESSES; k++) {
+					for (c = 0, b = 0; b < 8; b++)
+						if (cfag12864b_buffer
+							[i * CFAG12864B_ADDRESSES / 8
+							+ k / 8 + (j * 8 + b) *
+							CFAG12864B_WIDTH / 8]
+							& bit(k % 8))
+							c |= bit(b);
+					cfag12864b_writebyte(c);
+				}
+			}
+		}
+
+		memcpy(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE);
+	}
+
+	if (cfag12864b_updating)
+		cfag12864b_queue();
+}
+
+/*
+ * cfag12864b Exported Symbols
+ */
+
+EXPORT_SYMBOL_GPL(cfag12864b_buffer);
+EXPORT_SYMBOL_GPL(cfag12864b_get_rate);
+EXPORT_SYMBOL_GPL(cfag12864b_power_on);
+EXPORT_SYMBOL_GPL(cfag12864b_power_off);
+EXPORT_SYMBOL_GPL(cfag12864b_enable);
+EXPORT_SYMBOL_GPL(cfag12864b_disable);
+EXPORT_SYMBOL_GPL(cfag12864b_is_enabled);
+
+/*
+ * Module Init & Exit
+ */
+
+static int __init cfag12864b_init(void)
+{
+	int ret = -EINVAL;
+
+	if (PAGE_SIZE < CFAG12864B_SIZE) {
+		printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
+			"page size (%i) < cfag12864b size (%i)\n",
+			(unsigned int)PAGE_SIZE, CFAG12864B_SIZE);
+		ret = -ENOMEM;
+		goto none;
+	}
+
+	cfag12864b_buffer = (unsigned char *) __get_free_page(GFP_KERNEL);
+	if (cfag12864b_buffer == NULL) {
+		printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
+			"can't get a free page\n");
+		ret = -ENOMEM;
+		goto none;
+	}
+
+	cfag12864b_cache = kmalloc(sizeof(unsigned char) *
+		CFAG12864B_SIZE, GFP_KERNEL);
+	if (cfag12864b_buffer == NULL) {
+		printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
+			"can't alloc cache buffer (%i bytes)\n",
+			CFAG12864B_SIZE);
+		ret = -ENOMEM;
+		goto bufferalloced;
+	}
+
+	cfag12864b_workqueue = create_singlethread_workqueue(CFAG12864B_NAME);
+	if (cfag12864b_workqueue == NULL)
+		goto cachealloced;
+
+	memset(cfag12864b_buffer, 0, CFAG12864B_SIZE);
+
+	cfag12864b_clear();
+	cfag12864b_on();
+
+	return 0;
+
+cachealloced:
+	kfree(cfag12864b_cache);
+
+bufferalloced:
+	free_page((unsigned long) cfag12864b_buffer);
+
+none:
+	return ret;
+}
+
+static void __exit cfag12864b_exit(void)
+{
+	cfag12864b_disable();
+	cfag12864b_off();
+	destroy_workqueue(cfag12864b_workqueue);
+	kfree(cfag12864b_cache);
+	free_page((unsigned long) cfag12864b_buffer);
+}
+
+module_init(cfag12864b_init);
+module_exit(cfag12864b_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Miguel Ojeda Sandonis <maxextreme@gmail.com>");
+MODULE_DESCRIPTION("cfag12864b LCD driver");
diff --git a/drivers/video/display/cfag12864bfb.c b/drivers/video/display/cfag12864bfb.c
new file mode 100644
index 0000000..e51655f
--- /dev/null
+++ b/drivers/video/display/cfag12864bfb.c
@@ -0,0 +1,205 @@
+/*
+ *    Filename: cfag12864bfb.c
+ *     Version: 0.1.0
+ * Description: cfag12864b LCD framebuffer driver
+ *     License: GPLv2
+ *     Depends: cfag12864b
+ *
+ *      Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
+ *        Date: 2006-10-31
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/display.h>
+#include <linux/errno.h>
+#include <linux/fb.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <linux/cfag12864b.h>
+
+#define CFAG12864BFB_NAME "cfag12864bfb"
+
+static struct fb_info *fb;
+
+static char cfag12864bfb_name[] = CFAG12864BFB_NAME;
+static int cfag12864bfb_power;
+
+static struct fb_fix_screeninfo cfag12864bfb_fix __initdata = {
+	.id = CFAG12864BFB_NAME,
+	.type = FB_TYPE_PACKED_PIXELS,
+	.visual = FB_VISUAL_MONO10,
+	.xpanstep = 0,
+	.ypanstep = 0,
+	.ywrapstep = 0,
+	.line_length = CFAG12864B_WIDTH / 8,
+	.accel = FB_ACCEL_NONE,
+};
+
+static struct fb_var_screeninfo cfag12864bfb_var __initdata = {
+	.xres = CFAG12864B_WIDTH,
+	.yres = CFAG12864B_HEIGHT,
+	.xres_virtual = CFAG12864B_WIDTH,
+	.yres_virtual = CFAG12864B_HEIGHT,
+	.bits_per_pixel = 1,
+	.red = { 0, 1, 0 },
+      	.green = { 0, 1, 0 },
+      	.blue = { 0, 1, 0 },
+	.left_margin = 0,
+	.right_margin = 0,
+	.upper_margin = 0,
+	.lower_margin = 0,
+	.vmode = FB_VMODE_NONINTERLACED,
+};
+
+static int cfag12864bfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
+{
+	return vm_insert_page(vma, vma->vm_start,
+		virt_to_page(cfag12864b_buffer));
+}
+
+static struct fb_ops cfag12864bfb_ops = {
+	.owner = THIS_MODULE,
+	.fb_fillrect = cfb_fillrect,
+	.fb_copyarea = cfb_copyarea,
+	.fb_imageblit = cfb_imageblit,
+	.fb_mmap = cfag12864bfb_mmap,
+};
+
+static int cfag12864bfb_set_power(struct display_device *device)
+{
+	if (device->request_state > 0) {
+		cfag12864bfb_power = 1;
+		cfag12864b_power_on();
+	} else {
+		cfag12864bfb_power = 0;
+		cfag12864b_power_off();
+	}
+
+	return 0;
+}
+
+static int cfag12864bfb_get_power(struct display_device *device)
+{
+	return cfag12864bfb_power;
+}
+
+static int cfag12864bfb_probe(struct display_device *device, void *data)
+{
+	return 0;
+}
+
+static int cfag12864bfb_remove(struct display_device *device)
+{
+	return 0;
+}
+
+static struct display_driver cfag12864bfb_driver = {
+	.set_power = cfag12864bfb_set_power,
+	.get_power = cfag12864bfb_get_power,
+	.probe	= cfag12864bfb_probe,
+	.remove = cfag12864bfb_remove,
+};
+
+static struct display_device *cfag12864bfb_device;
+
+static int __init cfag12864bfb_init(void)
+{
+	int ret = -EINVAL;
+
+	if (cfag12864b_enable()) {
+		printk(KERN_ERR CFAG12864BFB_NAME ": ERROR: "
+			"can't enable cfag12864b refreshing (being used)\n");
+		ret = -ENODEV;
+		goto none;
+	}
+
+	fb = framebuffer_alloc(0, NULL);
+	if (!fb) {
+		printk(KERN_ERR CFAG12864BFB_NAME ": ERROR: "
+			"can't alloc framebuffer\n");
+		ret = -ENODEV;
+		goto enabled;
+	}
+
+	fb->screen_base = (char __iomem *) cfag12864b_buffer;
+	fb->screen_size = CFAG12864B_SIZE;
+	fb->fbops = &cfag12864bfb_ops;
+	fb->fix = cfag12864bfb_fix;
+	fb->var = cfag12864bfb_var;
+	fb->pseudo_palette = NULL;
+	fb->par = NULL;
+	fb->flags = FBINFO_FLAG_DEFAULT;
+
+	if (register_framebuffer(fb) < 0) {
+		printk(KERN_ERR CFAG12864BFB_NAME ": ERROR: "
+			"can't register framebuffer\n");
+		ret = -ENODEV;
+		goto fballoced;
+	}
+
+	cfag12864bfb_device = display_device_register(&cfag12864bfb_driver,
+		NULL, NULL);
+	if (!cfag12864bfb_device) {
+		printk(KERN_ERR CFAG12864BFB_NAME ": ERROR: "
+			"can't register display device\n");
+		ret = -ENODEV;
+		goto fbregistered;
+	}
+
+	cfag12864bfb_device->name = cfag12864bfb_name;
+	cfag12864bfb_device->owner = THIS_MODULE;
+	cfag12864bfb_device->request_state = cfag12864bfb_power = 1;
+
+	cfag12864b_power_on();
+
+	printk(KERN_INFO "fb%d: %s framebuffer device\n", fb->node,
+		fb->fix.id);
+
+	return 0;
+
+fbregistered:
+	unregister_framebuffer(fb);
+
+fballoced:
+	framebuffer_release(fb);
+
+enabled:
+	cfag12864b_disable();
+
+none:
+	return ret;
+}
+
+static void __exit cfag12864bfb_exit(void)
+{
+	display_device_unregister(cfag12864bfb_device);
+	unregister_framebuffer(fb);
+	framebuffer_release(fb);
+	cfag12864b_disable();
+}
+
+module_init(cfag12864bfb_init);
+module_exit(cfag12864bfb_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Miguel Ojeda Sandonis <maxextreme@gmail.com>");
+MODULE_DESCRIPTION("cfag12864bfb LCD framebuffer driver");
diff --git a/drivers/video/display/ks0108.c b/drivers/video/display/ks0108.c
new file mode 100644
index 0000000..a637575
--- /dev/null
+++ b/drivers/video/display/ks0108.c
@@ -0,0 +1,166 @@
+/*
+ *    Filename: ks0108.c
+ *     Version: 0.1.0
+ * Description: ks0108 LCD Controller driver
+ *     License: GPLv2
+ *     Depends: parport
+ *
+ *      Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
+ *        Date: 2006-10-31
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/io.h>
+#include <linux/parport.h>
+#include <linux/uaccess.h>
+#include <linux/ks0108.h>
+
+#define KS0108_NAME "ks0108"
+
+/*
+ * Module Parameters
+ */
+
+static unsigned int ks0108_port = CONFIG_KS0108_PORT;
+module_param(ks0108_port, uint, S_IRUGO);
+MODULE_PARM_DESC(ks0108_port, "Parallel port where the LCD is connected");
+
+static unsigned int ks0108_delay = CONFIG_KS0108_DELAY;
+module_param(ks0108_delay, uint, S_IRUGO);
+MODULE_PARM_DESC(ks0108_delay, "Delay between each control writing (microseconds)");
+
+/*
+ * Device
+ */
+
+static struct parport *ks0108_parport;
+static struct pardevice *ks0108_pardevice;
+
+/*
+ * ks0108 Exported Commands (don't lock)
+ *
+ *   You _should_ lock in the top driver: This functions _should not_
+ *   get race conditions in any way. Locking for each byte here would be
+ *   so slow and useless.
+ *
+ *   There are not bit definitions because they are not flags,
+ *   just arbitrary combinations defined by the documentation for each
+ *   function in the ks0108 LCD controller. If you want to know what means
+ *   a specific combination, look at the function's name.
+ *
+ *   The ks0108_writecontrol bits need to be reverted ^(0,1,3) because
+ *   the parallel port also revert them using a "not" logic gate.
+ */
+
+#define bit(n) (((unsigned char)1)<<(n))
+
+void ks0108_writedata(unsigned char byte)
+{
+	parport_write_data(ks0108_parport, byte);
+}
+
+void ks0108_writecontrol(unsigned char byte)
+{
+	udelay(ks0108_delay);
+	parport_write_control(ks0108_parport, byte ^ (bit(0) | bit(1) | bit(3)));
+}
+
+void ks0108_displaystate(unsigned char state)
+{
+	ks0108_writedata((state ? bit(0) : 0) | bit(1) | bit(2) | bit(3) | bit(4) | bit(5));
+}
+
+void ks0108_startline(unsigned char startline)
+{
+	ks0108_writedata(min(startline,(unsigned char)63) | bit(6) | bit(7));
+}
+
+void ks0108_address(unsigned char address)
+{
+	ks0108_writedata(min(address,(unsigned char)63) | bit(6));
+}
+
+void ks0108_page(unsigned char page)
+{
+	ks0108_writedata(min(page,(unsigned char)7) | bit(3) | bit(4) | bit(5) | bit(7));
+}
+
+EXPORT_SYMBOL_GPL(ks0108_writedata);
+EXPORT_SYMBOL_GPL(ks0108_writecontrol);
+EXPORT_SYMBOL_GPL(ks0108_displaystate);
+EXPORT_SYMBOL_GPL(ks0108_startline);
+EXPORT_SYMBOL_GPL(ks0108_address);
+EXPORT_SYMBOL_GPL(ks0108_page);
+
+/*
+ * Module Init & Exit
+ */
+
+static int __init ks0108_init(void)
+{
+	int result;
+	int ret = -EINVAL;
+
+	ks0108_parport = parport_find_base(ks0108_port);
+	if (ks0108_parport == NULL) {
+		printk(KERN_ERR KS0108_NAME ": ERROR: "
+			"parport didn't find %i port\n", ks0108_port);
+		goto none;
+	}
+
+	ks0108_pardevice = parport_register_device(ks0108_parport, KS0108_NAME,
+		NULL, NULL, NULL, PARPORT_DEV_EXCL, NULL);
+	if (ks0108_pardevice == NULL) {
+		printk(KERN_ERR KS0108_NAME ": ERROR: "
+			"parport didn't register new device\n");
+		goto none;
+	}
+
+	result = parport_claim(ks0108_pardevice);
+	if (result != 0) {
+		printk(KERN_ERR KS0108_NAME ": ERROR: "
+			"can't claim %i parport, maybe in use\n", ks0108_port);
+		ret = result;
+		goto registered;
+	}
+
+	return 0;
+
+registered:
+	parport_unregister_device(ks0108_pardevice);
+
+none:
+	return ret;
+}
+
+static void __exit ks0108_exit(void)
+{
+	parport_release(ks0108_pardevice);
+	parport_unregister_device(ks0108_pardevice);
+}
+
+module_init(ks0108_init);
+module_exit(ks0108_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Miguel Ojeda Sandonis <maxextreme@gmail.com>");
+MODULE_DESCRIPTION("ks0108 LCD Controller driver");
+
diff --git a/include/linux/cfag12864b.h b/include/linux/cfag12864b.h
new file mode 100644
index 0000000..5174670
--- /dev/null
+++ b/include/linux/cfag12864b.h
@@ -0,0 +1,91 @@
+/*
+ *    Filename: cfag12864b.h
+ *     Version: 0.1.0
+ * Description: cfag12864b LCD driver header
+ *     License: GPLv2
+ *
+ *      Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
+ *        Date: 2006-12-06
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#ifndef _CFAG12864B_H_
+#define _CFAG12864B_H_
+
+#define CFAG12864B_WIDTH	(128)
+#define CFAG12864B_HEIGHT	(64)
+#define CFAG12864B_CONTROLLERS	(2)
+#define CFAG12864B_PAGES	(8)
+#define CFAG12864B_ADDRESSES	(64)
+#define CFAG12864B_SIZE		((CFAG12864B_CONTROLLERS) * \
+				(CFAG12864B_PAGES) * \
+				(CFAG12864B_ADDRESSES))
+
+/*
+ * The driver will blit this buffer to the LCD
+ *
+ * Its size is CFAG12864B_SIZE.
+ */
+extern unsigned char * cfag12864b_buffer;
+
+/*
+ * Get the refresh rate of the LCD
+ *
+ * Returns the refresh rate (hertzs).
+ */
+extern unsigned int cfag12864b_get_rate(void);
+
+/*
+ * Power on the LCD
+ *
+ * Screen memory will be showed
+ */
+extern void cfag12864b_power_on(void);
+
+/*
+ * Power off the LCD
+ *
+ * Screen memory won't be showed
+ */
+extern void cfag12864b_power_off(void);
+
+/*
+ * Enable refreshing
+ *
+ * Returns 0 if successful (anyone was using it),
+ * or != 0 if failed (someone is using it).
+ */
+extern unsigned char cfag12864b_enable(void);
+
+/*
+ * Disable refreshing
+ *
+ * You should call this only when you finish using the LCD.
+ */
+extern void cfag12864b_disable(void);
+
+/*
+ * Is enabled refreshing? (is anyone using the module?)
+ *
+ * Returns 0 if refreshing is not enabled (anyone is using it),
+ * or != 0 if refreshing is enabled (someone is using it).
+ *
+ * Useful for buffer read-only modules.
+ */
+extern unsigned char cfag12864b_is_enabled(void);
+
+#endif /* _CFAG12864B_H_ */
+
diff --git a/include/linux/ks0108.h b/include/linux/ks0108.h
new file mode 100644
index 0000000..aca57f1
--- /dev/null
+++ b/include/linux/ks0108.h
@@ -0,0 +1,46 @@
+/*
+ *    Filename: ks0108.h
+ *     Version: 0.1.0
+ * Description: ks0108 LCD Controller driver header
+ *     License: GPLv2
+ *
+ *      Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
+ *        Date: 2006-12-06
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#ifndef _KS0108_H_
+#define _KS0108_H_
+
+/* Write a byte to the data port */
+extern void ks0108_writedata(unsigned char byte);
+
+/* Write a byte to the control port */
+extern void ks0108_writecontrol(unsigned char byte);
+
+/* Set the controller's current display state (0..1) */
+extern void ks0108_displaystate(unsigned char state);
+
+/* Set the controller's current startline (0..63) */
+extern void ks0108_startline(unsigned char startline);
+
+/* Set the controller's current address (0..63) */
+extern void ks0108_address(unsigned char address);
+
+/* Set the controller's current page (0..7) */
+extern void ks0108_page(unsigned char page);
+
+#endif /* _KS0108_H_ */

Re: Display class

[Miguel Ojeda]

On 12/6/06, Miguel Ojeda Sandonis <maxextreme@gmail.com> wrote:
> Ok, here is the patch (against git7+displayclass) which moves auxdisplay/*
> to video/display/* and start using the display class.
>
> It is just a draft, but there isn't much code changed from -mm2.
>
>   - I would remove "struct device *dev, void *devdata" of display_device_register()
>     Are they neccesary for other display drivers? I have to pass NULL right now.
>
>   - I would add a paramtere ("char *name") to display_device_register() so we
>     set the name when registering. Right now I have to set my name after inited,
>     and this is a Linux module and not a person borning, right? ;)
>
>   - I would add a read/writeable attr called "rate" for set/unset the refresh rate
>     of a display.
>
>   - I was going to maintain the drivers/auxdisplay/* tree.
>     Are you going to maintain the driver? I think so, just for being sure.

I meant display driver (display/*).

>
> P.S.
>
>   When I was working at 2.6.19-rc6-mm2 it worked all fine, but now
>   I have copied it to git7 I'm getting some weird segmentation faults
>   (oops) when at cfag12864bfb_init, at mutex_lock() in
>   display_device_unregister module... I think unrelated (?), but I will
>

I meant display_device_unregister function of display-sysfs.c

--

The changes have been made in driver/video/display/cfag12864bfb.c, so
please focus the review on it.

Thanks

Re: Display class

[James Simmons]

>   - I would remove "struct device *dev, void *devdata" of display_device_register()
>     Are they neccesary for other display drivers? I have to pass NULL right now.

Yes. Passing in a struct device allows you a link between the device and 
the class. If you pass in the device for the parport a link to the parport 
device would exist in you displayX directory. The devdata is used by the 
probe function to get data about the monitor if it is not NULL.

In the case of most desktop monitors they have EDID blocks. You can 
retrieve them (devdata) and it gets parsed thus you have detail data
about the monitor. In your case it can be null. 

>   - I would add a paramtere ("char *name") to display_device_register() so we
>     set the name when registering. Right now I have to set my name after inited,
>     and this is a Linux module and not a person borning, right? ;)

The probe function gets this for you. In your case you would have a probe 
method that would just fill in the name of the LCD. For me using the ACPI 
video driver I get the name for my monitor

LEN  15"XGA 200nit

Which is the manufacturer - monitor id - ascii block.

>   - I would add a read/writeable attr called "rate" for set/unset the refresh rate
>     of a display.

I suggest creating a group for your driver. See device.h for 
group_attributes.
 
>   - I was going to maintain the drivers/auxdisplay/* tree.
>     Are you going to maintain the driver? I think so, just for being sure.

Yes. I need it for the ACPI video and fbdev layer. Remember its in the 
early stages yet. 

> P.S.
> 
>   When I was working at 2.6.19-rc6-mm2 it worked all fine, but now
>   I have copied it to git7 I'm getting some weird segmentation faults
>   (oops) when at cfag12864bfb_init, at mutex_lock() in
>   display_device_unregister module... I think unrelated (?), but I will
>   look for some mistake I made.

Did you solve the problem?

Re: Display class

[Miguel Ojeda]

On 12/7/06, James Simmons <jsimmons@infradead.org> wrote:
>
> >   - I would remove "struct device *dev, void *devdata" of display_device_register()
> >     Are they neccesary for other display drivers? I have to pass NULL right now.
>
> Yes. Passing in a struct device allows you a link between the device and
> the class. If you pass in the device for the parport a link to the parport
> device would exist in you displayX directory. The devdata is used by the
> probe function to get data about the monitor if it is not NULL.
>
> In the case of most desktop monitors they have EDID blocks. You can
> retrieve them (devdata) and it gets parsed thus you have detail data
> about the monitor. In your case it can be null.
>
> >   - I would add a paramtere ("char *name") to display_device_register() so we
> >     set the name when registering. Right now I have to set my name after inited,
> >     and this is a Linux module and not a person borning, right? ;)
>
> The probe function gets this for you. In your case you would have a probe
> method that would just fill in the name of the LCD. For me using the ACPI
> video driver I get the name for my monitor
>
> LEN  15"XGA 200nit
>
> Which is the manufacturer - monitor id - ascii block.
>
> >   - I would add a read/writeable attr called "rate" for set/unset the refresh rate
> >     of a display.
>
> I suggest creating a group for your driver. See device.h for
> group_attributes.
>
> >   - I was going to maintain the drivers/auxdisplay/* tree.
> >     Are you going to maintain the driver? I think so, just for being sure.
>
> Yes. I need it for the ACPI video and fbdev layer. Remember its in the
> early stages yet.
>
> > P.S.
> >
> >   When I was working at 2.6.19-rc6-mm2 it worked all fine, but now
> >   I have copied it to git7 I'm getting some weird segmentation faults
> >   (oops) when at cfag12864bfb_init, at mutex_lock() in
> >   display_device_unregister module... I think unrelated (?), but I will
> >   look for some mistake I made.
>
> Did you solve the problem?
>

I didn't look further, but I will be able to try again in some hours.
Anyway, the problem is probably at cfag12864bfb.c (as it was almost
the only file I modified from -mm2); but I can't tell where the
problem is as I tried just a few times.

Please review cfag12864bfb_init/_exit to check if your code/class is
intended to be used that way, I will focus on the segfaults.

Greets!

-- 
Miguel Ojeda
http://maxextreme.googlepages.com/index.htm

Re: Display class

[Miguel Ojeda]

On 12/7/06, James Simmons <jsimmons@infradead.org> wrote:
>
> > P.S.
> >
> >   When I was working at 2.6.19-rc6-mm2 it worked all fine, but now
> >   I have copied it to git7 I'm getting some weird segmentation faults
> >   (oops) when at cfag12864bfb_init, at mutex_lock() in
> >   display_device_unregister module... I think unrelated (?), but I will
> >   look for some mistake I made.
>
> Did you solve the problem?
>
>

Ok, found it. It was at cfag12864bfb_init:

	cfag12864bfb_device = display_device_register(&cfag12864bfb_driver,
		NULL, NULL);
	if (!cfag12864bfb_device) {
		printk(KERN_ERR CFAG12864BFB_NAME ": ERROR: "
			"can't register display device\n");
		ret = -ENODEV;
		goto fbregistered;
	}

	/*cfag12864bfb_device->name = cfag12864bfb_name;
	cfag12864bfb_device->request_state = 1;*/

	cfag12864bfb_power = 1;
	cfag12864b_power_on();

The commented code. I have exchange it to pass the name through probe
as you suggested, still, it brokes when rmmoding it at
display_device_unregister:

root@morfeo:/usr/src/git/linux-2.6.19-git12# dmesg
[ 1593.770774] BUG: unable to handle kernel paging request at virtual
address ff fffffc
[ 1593.770780]  printing eip:
[ 1593.770782] c02e3f3f
[ 1593.770784] *pde = 00003067
[ 1593.770787] Oops: 0002 [#1]
[ 1593.770788] PREEMPT SMP
[ 1593.770791] Modules linked in: cfag12864bfb display cfag12864b
ks0108 ppdev n ls_utf8 ntfs ipv6 md_mod af_packet tsdev snd_intel8x0
snd_ac97_codec snd_ac97_bu s snd_pcm_oss snd_mixer_oss sk98lin psmouse
snd_pcm snd_timer snd soundcore parp ort_pc parport skge floppy
snd_page_alloc serio_raw pcspkr rtc intel_agp agpgart  evdev dm_mirror
dm_mod ide_generic ide_disk ide_cd cdrom piix generic vga16fb v
gastate
[ 1593.770829] CPU:    1
[ 1593.770829] EIP:    0060:[<c02e3f3f>]    Not tainted VLI
[ 1593.770831] EFLAGS: 00010282   (2.6.19-git12 #1)
[ 1593.770838] EIP is at mutex_lock+0x0/0xb
[ 1593.770841] eax: fffffffc   ebx: fffffff4   ecx: 00000002   edx: f9955f00
[ 1593.770844] esi: 00000000   edi: fffffffc   ebp: e2ae6000   esp: e2ae7f48
[ 1593.770847] ds: 007b   es: 007b   ss: 0068
[ 1593.770850] Process rmmod (pid: 13348, ti=e2ae6000 task=dfd6f030
task.ti=e2ae 6000)
[ 1593.770852] Stack: f9952114 f9955e00 00000000 00000003 f9955066
c01374a1 6761 6663 36383231
[ 1593.770860]        62666234 b7eec000 f7d68780 c014f67b ffffffff
b7eed000 f7d6 8784 e2616aac
[ 1593.770868]        b7eed000 e2616ab8 e2616aac f7d68780 00d687b4
f9955e00 0000 0880 e2ae7fa8
[ 1593.770877] Call Trace:
[ 1593.770879]  [<f9952114>] display_device_unregister+0x13/0x51 [display]
[ 1593.770888]  [<f9955066>] cfag12864bfb_exit+0xa/0x23 [cfag12864bfb]
[ 1593.770893]  [<c01374a1>] sys_delete_module+0x11d/0x189
[ 1593.770902]  [<c014f67b>] do_munmap+0x177/0x1d0
[ 1593.770913]  [<c0102d76>] sysenter_past_esp+0x5f/0x85
[ 1593.770922]  [<c02e0033>] atm_dev_ioctl+0x35f/0x655
[ 1593.770929]  =======================
[ 1593.770931] Code: c0 8d 54 24 08 8d 4c 24 1c 89 4c 24 1c 89 4c 24
20 8b 4c 24  38 89 0c 24 89 e9 8b 44 24 04 e8 3f ff ff ff 83 c4 24 5b
5e 5f 5d c3 <f0> ff 08  79 05 e8 1b 01 00 00 c3 f0 ff 00 7f 05 e8 34
00 00 00
[ 1593.770973] EIP: [<c02e3f3f>] mutex_lock+0x0/0xb SS:ESP 0068:e2ae7f48
[ 1593.770979]

-- 
Miguel Ojeda
http://maxextreme.googlepages.com/index.htm

Re: Display class

[Greg KH]

On Sat, Jan 13, 2007 at 10:40:55PM +0000, James Simmons wrote:
> 
> > Hi,
> > 
> > On Tuesday 05 December 2006 13:03, James Simmons wrote:
> > > +int probe_edid(struct display_device *dev, void *data)
> > > +{
> > > +???????struct fb_monspecs spec;
> > > +???????ssize_t size = 45;
> 
> That code was only for testing. I do have new core code. Andrew could 
> you merge this patch as it is against the -mm tree.
> 
> This new class provides a way common interface for various types of 
> displays such as LCD, CRT, LVDS etc. It is a expansion of the lcd
> class to include other types of displays.

Have you worked with the DRM developers who also need to tie into this
CRT class somehow?

thanks,

greg k-h

Re: Display class

[Greg KH]

On Sat, Jan 13, 2007 at 10:40:55PM +0000, James Simmons wrote:
> 
> > Hi,
> > 
> > On Tuesday 05 December 2006 13:03, James Simmons wrote:
> > > +int probe_edid(struct display_device *dev, void *data)
> > > +{
> > > +???????struct fb_monspecs spec;
> > > +???????ssize_t size = 45;
> 
> That code was only for testing. I do have new core code. Andrew could 
> you merge this patch as it is against the -mm tree.
> 
> This new class provides a way common interface for various types of 
> displays such as LCD, CRT, LVDS etc. It is a expansion of the lcd
> class to include other types of displays.

Any chance you can change this to use "struct device" instead of "struct
class_device" so I don't have to convert it myself in the next few weeks
if it ever gets merged?  :)

The functionality will be the same, if not, please let me know what
problems you have with the change.

thanks,

greg k-h

Re: Display class

[James Simmons]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 11557 bytes --]


> Hi,
> 
> On Tuesday 05 December 2006 13:03, James Simmons wrote:
> > +int probe_edid(struct display_device *dev, void *data)
> > +{
> > +       struct fb_monspecs spec;
> > +       ssize_t size = 45;

That code was only for testing. I do have new core code. Andrew could 
you merge this patch as it is against the -mm tree.

This new class provides a way common interface for various types of 
displays such as LCD, CRT, LVDS etc. It is a expansion of the lcd
class to include other types of displays.
  
diff -urN linux-2.6.20-rc3/drivers/video/display/display-sysfs.c linux-2.6.20-rc3-display/drivers/video/display/display-sysfs.c
--- linux-2.6.20-rc3/drivers/video/display/display-sysfs.c	1969-12-31 19:00:00.000000000 -0500
+++ linux-2.6.20-rc3-display/drivers/video/display/display-sysfs.c	2007-01-13 16:22:54.000000000 -0500
@@ -0,0 +1,208 @@
+/*
+ *  display.c - Display output driver
+ *
+ *  Copyright (C) 2007 James Simmons <jsimmons@infradead.org>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/module.h>
+#include <linux/display.h>
+#include <linux/err.h>
+#include <linux/ctype.h>
+
+static ssize_t display_show_name(struct class_device *cdev, char *buf)
+{
+	struct display_device *dsp = to_display_device(cdev);
+	return snprintf(buf, PAGE_SIZE, "%s\n", dsp->name);
+}
+
+static ssize_t display_show_type(struct class_device *cdev, char *buf)
+{
+	struct display_device *dsp = to_display_device(cdev);
+	return snprintf(buf, PAGE_SIZE, "%s\n", dsp->driver->type);
+}
+
+static ssize_t display_show_power(struct class_device *cdev, char *buf)
+{
+	struct display_device *dsp = to_display_device(cdev);
+	ssize_t ret = -ENXIO;
+
+	mutex_lock(&dsp->lock);
+	if (likely(dsp->driver->get_power))
+		ret = sprintf(buf,"%.8x\n", dsp->driver->get_power(dsp));
+	mutex_unlock(&dsp->lock);
+	return ret;
+}
+
+static ssize_t display_store_power(struct class_device *cdev,
+	const char *buf, size_t count)
+{
+	struct display_device *dsp = to_display_device(cdev);
+	ssize_t size;
+	char *endp;
+	int power;
+
+	power = simple_strtoul(buf, &endp, 0);
+	size = endp - buf;
+	if (*endp && isspace(*endp))
+		size++;
+	if (size != count)
+		return -EINVAL;
+
+	mutex_lock(&dsp->lock);
+	if (likely(dsp->driver->set_power)) {
+		dsp->request_state = power;
+		dsp->driver->set_power(dsp);
+	}
+	mutex_unlock(&dsp->lock);
+	return count;
+}
+
+static ssize_t display_show_contrast(struct class_device *cdev, char *buf)
+{
+	struct display_device *dsp = to_display_device(cdev);
+	ssize_t rc = -ENXIO;
+
+	mutex_lock(&dsp->lock);
+	if (likely(dsp->driver) && dsp->driver->get_contrast)
+		rc = sprintf(buf, "%d\n", dsp->driver->get_contrast(dsp));
+	mutex_unlock(&dsp->lock);
+	return rc;
+}
+
+static ssize_t display_store_contrast(struct class_device *cdev, const char *buf, size_t count)
+{
+	
+	struct display_device *dsp = to_display_device(cdev);
+	ssize_t ret = -EINVAL, size;
+	int contrast;
+	char *endp;
+
+	contrast = simple_strtoul(buf, &endp, 0);
+	size = endp - buf;
+
+	if (*endp && isspace(*endp))
+		size++;
+
+	if (size != count)
+		return ret;
+
+	mutex_lock(&dsp->lock);
+	if (likely(dsp->driver && dsp->driver->set_contrast)) {
+		pr_debug("display: set contrast to %d\n", contrast);
+		dsp->driver->set_contrast(dsp, contrast);
+		ret = count;
+	}
+	mutex_unlock(&dsp->lock);
+	return ret;
+}
+
+static ssize_t display_show_max_contrast(struct class_device *cdev, char *buf)
+{
+	struct display_device *dsp = to_display_device(cdev);
+	ssize_t rc = -ENXIO;
+
+	mutex_lock(&dsp->lock);
+	if (likely(dsp->driver))
+		rc = sprintf(buf, "%d\n", dsp->driver->max_contrast);
+	mutex_unlock(&dsp->lock);
+	return rc;
+}
+
+static void display_class_release(struct class_device *dev)
+{
+	struct display_device *dsp = to_display_device(dev);
+	kfree(dsp);
+}
+
+static struct class_device_attribute display_attributes[] = {
+	__ATTR(name, S_IRUGO, display_show_name, NULL),
+	__ATTR(type, S_IRUGO, display_show_type, NULL),
+	__ATTR(power, S_IRUGO | S_IWUSR, display_show_power, display_store_power),
+	__ATTR(contrast, S_IRUGO | S_IWUSR, display_show_contrast, display_store_contrast),
+	__ATTR(max_contrast, S_IRUGO, display_show_max_contrast, NULL),
+};
+
+static struct class display_class = {
+	.name = "display",
+	.release = display_class_release,
+	.class_dev_attrs = display_attributes,
+};
+
+static int index;
+
+struct display_device *display_device_register(struct display_driver *driver,
+						struct device *dev, void *devdata)
+{
+	struct display_device *new_dev;
+	int ret = -ENOMEM;
+
+	if (unlikely(!driver))
+		return ERR_PTR(-EINVAL);
+
+	new_dev = kzalloc(sizeof(struct display_device), GFP_KERNEL);
+	if (likely(new_dev) && unlikely(driver->probe(new_dev, devdata))) {
+		mutex_init(&new_dev->lock);
+
+		new_dev->class_dev.groups = &driver->type_prop; 
+		new_dev->class_dev.class = &display_class;
+		new_dev->class_dev.dev = dev;
+		new_dev->driver = driver;
+
+		sprintf(new_dev->class_dev.class_id, "display%d", index++);
+		class_set_devdata(&new_dev->class_dev, devdata);
+		ret = class_device_register(&new_dev->class_dev);
+	}
+	if (unlikely(ret)) {
+		kfree(new_dev);
+		new_dev = ERR_PTR(ret);
+	}
+	return new_dev;
+}
+EXPORT_SYMBOL(display_device_register);
+
+void display_device_unregister(struct display_device *dev)
+{
+	if (!dev)
+		return;
+	mutex_lock(&dev->lock);
+	class_device_unregister(&dev->class_dev);
+	dev->driver = NULL;
+	index--;
+	mutex_unlock(&dev->lock);
+	kfree(dev);
+}
+EXPORT_SYMBOL(display_device_unregister);
+
+static void __exit display_class_exit(void)
+{
+	class_unregister(&display_class);
+}
+
+static int __init display_class_init(void)
+{
+	return class_register(&display_class);
+}
+
+postcore_initcall(display_class_init);
+module_exit(display_class_exit);
+
+MODULE_DESCRIPTION("Display Hardware handling");
+MODULE_AUTHOR("James Simmons <jsimmons@infradead.org>");
+MODULE_LICENSE("GPL");
diff -urN linux-2.6.20-rc3/drivers/video/display/Kconfig linux-2.6.20-rc3-display/drivers/video/display/Kconfig
--- linux-2.6.20-rc3/drivers/video/display/Kconfig	1969-12-31 19:00:00.000000000 -0500
+++ linux-2.6.20-rc3-display/drivers/video/display/Kconfig	2007-01-13 16:00:51.000000000 -0500
@@ -0,0 +1,24 @@
+#
+# Display drivers configuration
+#
+
+menu "Display device support"
+
+config DISPLAY_SUPPORT
+	tristate "Display panel/monitor support"
+	---help---
+	  This framework adds support for low-level control of a display.
+	  This includes support for power.
+
+	  Enable this to be able to choose the drivers for controlling the
+	  physical display panel/monitor on some platforms. This not only
+	  covers LCD displays for PDAs but also other types of displays
+	  such as CRT, TVout etc.
+
+	  To have support for your specific display panel you will have to
+	  select the proper drivers which depend on this option.
+
+comment "Display hardware drivers"
+	depends on DISPLAY_SUPPORT
+
+endmenu
diff -urN linux-2.6.20-rc3/drivers/video/display/Makefile linux-2.6.20-rc3-display/drivers/video/display/Makefile
--- linux-2.6.20-rc3/drivers/video/display/Makefile	1969-12-31 19:00:00.000000000 -0500
+++ linux-2.6.20-rc3-display/drivers/video/display/Makefile	2007-01-13 16:01:03.000000000 -0500
@@ -0,0 +1,6 @@
+# Display drivers
+
+display-objs				:= display-sysfs.o
+
+obj-$(CONFIG_DISPLAY_SUPPORT)		+= display.o
+
diff -urN linux-2.6.20-rc3/drivers/video/Kconfig linux-2.6.20-rc3-display/drivers/video/Kconfig
--- linux-2.6.20-rc3/drivers/video/Kconfig	2007-01-08 14:00:26.000000000 -0500
+++ linux-2.6.20-rc3-display/drivers/video/Kconfig	2007-01-13 09:23:03.000000000 -0500
@@ -6,6 +6,7 @@
 
 if SYSFS
 	source "drivers/video/backlight/Kconfig"
+	source "drivers/video/display/Kconfig"
 endif
 
 config FB
diff -urN linux-2.6.20-rc3/drivers/video/Makefile linux-2.6.20-rc3-display/drivers/video/Makefile
--- linux-2.6.20-rc3/drivers/video/Makefile	2007-01-08 14:00:26.000000000 -0500
+++ linux-2.6.20-rc3-display/drivers/video/Makefile	2007-01-13 09:22:40.000000000 -0500
@@ -12,7 +12,7 @@
 
 obj-$(CONFIG_VT)		  += console/
 obj-$(CONFIG_LOGO)		  += logo/
-obj-$(CONFIG_SYSFS)		  += backlight/
+obj-$(CONFIG_SYSFS)		  += backlight/ display/
 
 obj-$(CONFIG_FB_CFB_FILLRECT)  += cfbfillrect.o
 obj-$(CONFIG_FB_CFB_COPYAREA)  += cfbcopyarea.o
diff -urN linux-2.6.20-rc3/include/linux/display.h linux-2.6.20-rc3-display/include/linux/display.h
--- linux-2.6.20-rc3/include/linux/display.h	1969-12-31 19:00:00.000000000 -0500
+++ linux-2.6.20-rc3-display/include/linux/display.h	2007-01-13 16:23:51.000000000 -0500
@@ -0,0 +1,60 @@
+/*
+ *  Copyright (C) 2006 James Simmons <jsimmons@infradead.org>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#ifndef _LINUX_DISPLAY_H
+#define _LINUX_DISPLAY_H
+
+#include <linux/device.h>
+
+struct display_device;
+
+/* This structure defines all the properties of a Display. */
+struct display_driver {
+	int (*set_power)(struct display_device *);
+	int (*get_power)(struct display_device *);
+	int (*set_contrast)(struct display_device *, unsigned int);
+	int (*get_contrast)(struct display_device *);
+	int (*probe)(struct display_device *, void *);
+	int (*remove)(struct display_device *);
+	struct attribute_group *type_prop;
+	int max_contrast;
+	char type[16];
+};
+
+struct display_device {
+	struct module *owner;	/* Owner module */
+	char *name;
+	struct mutex lock;
+	int request_state;
+	struct display_driver *driver;
+	struct class_device class_dev;		/* The class device structure */
+};
+
+extern struct display_device *display_device_register(struct display_driver *driver,
+					struct device *dev, void *devdata);
+extern void display_device_unregister(struct display_device *dev);
+
+extern int display_probe_edid(struct display_device *dev, void *devdata);
+
+#define to_display_device(obj) container_of(obj, struct display_device, class_dev)
+
+#endif

Re: Display class

[Dmitry Torokhov]

Hi,

On Tuesday 05 December 2006 13:03, James Simmons wrote:
> +int probe_edid(struct display_device *dev, void *data)
> +{
> +       struct fb_monspecs spec;
> +       ssize_t size = 45;

const ssize_t size = 45? 

> +
> +       dev->name = kzalloc(size, GFP_KERNEL);

Why do you need kzalloc here?

> +       fb_edid_to_monspecs((unsigned char *) data, &spec);
> +       strcpy(dev->name, spec.manufacturer);

You seem to be overwriting dev->name in the very next line?

> +       return snprintf(dev->name, size, "%s %s %s\n", spec.manufacturer, spec.monitor, spec.ascii);
> 

Is result of snprintf interesting to the callers?

-- 
Dmitry

Re: Display class

[Randy Dunlap]

On Wed, 6 Dec 2006 15:10:44 +0000 (GMT) James Simmons wrote:

> 
> > > of Mr. Yu for acpi. Also this class could in time replace the lcd class 
> > > located in the backlight directory since a lcd is a type of display.
> > > The final hope is that the purpose auxdisplay could fall under this 
> > > catergory.
> > > 
> > > P.S
> > >    I know the edid parsing would have to be pulled out of the fbdev layer.
> 
> That patch was rought draft for feedback. I applied your comments. This 
> patch actually works. It includes my backlight fix as well.

BTW, this patch version contains trailing whitespace
which should be cleaned up:

Warning: trailing whitespace in lines 33,158 of drivers/acpi/video.c
Warning: trailing whitespace in line 10 of drivers/video/display/Kconfig
Warning: trailing whitespace in line 41 of include/linux/display.h
Warning: trailing whitespace in lines 49,1053,1084,1133 of drivers/video/Kconfig
Warning: trailing whitespace in line 3 of drivers/video/display/Makefile

---
~Randy

Re: Display class

[James Simmons]

> > > > That patch was rought draft for feedback. I applied your comments. This 
> > > > patch actually works. It includes my backlight fix as well.
> > > 
> > > Glad to hear it.  I had to make the following changes
> > > in order for it to build.
> > > However, I still have build errors for aty.
> > 
> > Ug. I see another problem. I had backlight completly compiled as a 
> > module! Thus it hid these compile errors. So we need also a 
> > CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE check as well. Can sysfs handle this 
> > well or would it be better the the backlight class be a boolean instead?
> 
> SCSI works as a module and it uses sysfs.
> See drivers/scsi/scsi_sysfs.c.
> Does that answer your question?  I wasn't quite sure what
> the question was.

I'm scratching my head on how to configure a modular driver and 
two modular sysfs classes. 
 
> Next question, based on:
> drivers/built-in.o: In function `probe_edid':
> (.text.probe_edid+0x42): undefined reference to `fb_edid_to_monspecs'
> 
> Should backlight and/or display support depend on
> CONFIG_FB?  Right now they don't, so the above can happen...

I already sent a patch to Andrew to make backlight/lcd work independent of
CONFIG_FB. Display is still in the alpha stage. In time it will work 
independent of CONFIG_FB.

Re: Display class

[Randy Dunlap]

On Wed, 6 Dec 2006 18:24:08 +0000 (GMT) James Simmons wrote:

> 
> > > That patch was rought draft for feedback. I applied your comments. This 
> > > patch actually works. It includes my backlight fix as well.
> > 
> > Glad to hear it.  I had to make the following changes
> > in order for it to build.
> > However, I still have build errors for aty.
> 
> Ug. I see another problem. I had backlight completly compiled as a 
> module! Thus it hid these compile errors. So we need also a 
> CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE check as well. Can sysfs handle this 
> well or would it be better the the backlight class be a boolean instead?

SCSI works as a module and it uses sysfs.
See drivers/scsi/scsi_sysfs.c.
Does that answer your question?  I wasn't quite sure what
the question was.

Next question, based on:
drivers/built-in.o: In function `probe_edid':
(.text.probe_edid+0x42): undefined reference to `fb_edid_to_monspecs'

Should backlight and/or display support depend on
CONFIG_FB?  Right now they don't, so the above can happen...

---
~Randy

Re: Display class

[James Simmons]

> > That patch was rought draft for feedback. I applied your comments. This 
> > patch actually works. It includes my backlight fix as well.
> 
> Glad to hear it.  I had to make the following changes
> in order for it to build.
> However, I still have build errors for aty.

Ug. I see another problem. I had backlight completly compiled as a 
module! Thus it hid these compile errors. So we need also a 
CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE check as well. Can sysfs handle this 
well or would it be better the the backlight class be a boolean instead?

 
> ---
> From: Randy Dunlap <randy.dunlap@oracle.com>
> 
> Replace CONFIG_FB_BACKLIGHT with CONFIG_BACKLIGHT_CLASS_DEVICE
> in include/linux/fb.h and drivers/video/fbsysfs.c
> to match Kconfig changes.
> 
> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
> ---
>  drivers/video/fbsysfs.c |    8 ++++----
>  include/linux/fb.h      |    4 ++--
>  2 files changed, 6 insertions(+), 6 deletions(-)
> 
> --- linux-2.6.19-git7.orig/include/linux/fb.h
> +++ linux-2.6.19-git7/include/linux/fb.h
> @@ -367,7 +367,7 @@ struct fb_cursor {
>  	struct fb_image	image;	/* Cursor image */
>  };
>  
> -#ifdef CONFIG_FB_BACKLIGHT
> +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
>  /* Settings for the generic backlight code */
>  #define FB_BACKLIGHT_LEVELS	128
>  #define FB_BACKLIGHT_MAX	0xFF
> @@ -759,7 +759,7 @@ struct fb_info {
>  	struct list_head modelist;      /* mode list */
>  	struct fb_videomode *mode;	/* current mode */
>  
> -#ifdef CONFIG_FB_BACKLIGHT
> +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
>  	/* Lock ordering:
>  	 * bl_mutex (protects bl_dev and bl_curve)
>  	 *   bl_dev->sem (backlight class)
> --- linux-2.6.19-git7.orig/drivers/video/fbsysfs.c
> +++ linux-2.6.19-git7/drivers/video/fbsysfs.c
> @@ -58,7 +58,7 @@ struct fb_info *framebuffer_alloc(size_t
>  
>  	info->device = dev;
>  
> -#ifdef CONFIG_FB_BACKLIGHT
> +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
>  	mutex_init(&info->bl_mutex);
>  #endif
>  
> @@ -411,7 +411,7 @@ static ssize_t show_fbstate(struct devic
>  	return snprintf(buf, PAGE_SIZE, "%d\n", fb_info->state);
>  }
>  
> -#ifdef CONFIG_FB_BACKLIGHT
> +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
>  static ssize_t store_bl_curve(struct device *device,
>  			      struct device_attribute *attr,
>  			      const char *buf, size_t count)
> @@ -500,7 +500,7 @@ static struct device_attribute device_at
>  	__ATTR(stride, S_IRUGO, show_stride, NULL),
>  	__ATTR(rotate, S_IRUGO|S_IWUSR, show_rotate, store_rotate),
>  	__ATTR(state, S_IRUGO|S_IWUSR, show_fbstate, store_fbstate),
> -#ifdef CONFIG_FB_BACKLIGHT
> +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
>  	__ATTR(bl_curve, S_IRUGO|S_IWUSR, show_bl_curve, store_bl_curve),
>  #endif
>  };
> @@ -541,7 +541,7 @@ void fb_cleanup_device(struct fb_info *f
>  	}
>  }
>  
> -#ifdef CONFIG_FB_BACKLIGHT
> +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
>  /* This function generates a linear backlight curve
>   *
>   *     0: off
> 

Re: Display class

[Randy Dunlap]

On Wed, 6 Dec 2006 15:10:44 +0000 (GMT) James Simmons wrote:

> 
> > > of Mr. Yu for acpi. Also this class could in time replace the lcd class 
> > > located in the backlight directory since a lcd is a type of display.
> > > The final hope is that the purpose auxdisplay could fall under this 
> > > catergory.
> > > 
> > > P.S
> > >    I know the edid parsing would have to be pulled out of the fbdev layer.
> 
> That patch was rought draft for feedback. I applied your comments. This 
> patch actually works. It includes my backlight fix as well.

Glad to hear it.  I had to make the following changes
in order for it to build.
However, I still have build errors for aty.

---
From: Randy Dunlap <randy.dunlap@oracle.com>

Replace CONFIG_FB_BACKLIGHT with CONFIG_BACKLIGHT_CLASS_DEVICE
in include/linux/fb.h and drivers/video/fbsysfs.c
to match Kconfig changes.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
---
 drivers/video/fbsysfs.c |    8 ++++----
 include/linux/fb.h      |    4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

--- linux-2.6.19-git7.orig/include/linux/fb.h
+++ linux-2.6.19-git7/include/linux/fb.h
@@ -367,7 +367,7 @@ struct fb_cursor {
 	struct fb_image	image;	/* Cursor image */
 };
 
-#ifdef CONFIG_FB_BACKLIGHT
+#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
 /* Settings for the generic backlight code */
 #define FB_BACKLIGHT_LEVELS	128
 #define FB_BACKLIGHT_MAX	0xFF
@@ -759,7 +759,7 @@ struct fb_info {
 	struct list_head modelist;      /* mode list */
 	struct fb_videomode *mode;	/* current mode */
 
-#ifdef CONFIG_FB_BACKLIGHT
+#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
 	/* Lock ordering:
 	 * bl_mutex (protects bl_dev and bl_curve)
 	 *   bl_dev->sem (backlight class)
--- linux-2.6.19-git7.orig/drivers/video/fbsysfs.c
+++ linux-2.6.19-git7/drivers/video/fbsysfs.c
@@ -58,7 +58,7 @@ struct fb_info *framebuffer_alloc(size_t
 
 	info->device = dev;
 
-#ifdef CONFIG_FB_BACKLIGHT
+#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
 	mutex_init(&info->bl_mutex);
 #endif
 
@@ -411,7 +411,7 @@ static ssize_t show_fbstate(struct devic
 	return snprintf(buf, PAGE_SIZE, "%d\n", fb_info->state);
 }
 
-#ifdef CONFIG_FB_BACKLIGHT
+#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
 static ssize_t store_bl_curve(struct device *device,
 			      struct device_attribute *attr,
 			      const char *buf, size_t count)
@@ -500,7 +500,7 @@ static struct device_attribute device_at
 	__ATTR(stride, S_IRUGO, show_stride, NULL),
 	__ATTR(rotate, S_IRUGO|S_IWUSR, show_rotate, store_rotate),
 	__ATTR(state, S_IRUGO|S_IWUSR, show_fbstate, store_fbstate),
-#ifdef CONFIG_FB_BACKLIGHT
+#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
 	__ATTR(bl_curve, S_IRUGO|S_IWUSR, show_bl_curve, store_bl_curve),
 #endif
 };
@@ -541,7 +541,7 @@ void fb_cleanup_device(struct fb_info *f
 	}
 }
 
-#ifdef CONFIG_FB_BACKLIGHT
+#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
 /* This function generates a linear backlight curve
  *
  *     0: off

Re: Display class

[James Simmons]

> > of Mr. Yu for acpi. Also this class could in time replace the lcd class 
> > located in the backlight directory since a lcd is a type of display.
> > The final hope is that the purpose auxdisplay could fall under this 
> > catergory.
> > 
> > P.S
> >    I know the edid parsing would have to be pulled out of the fbdev layer.

That patch was rought draft for feedback. I applied your comments. This 
patch actually works. It includes my backlight fix as well.

diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/acpi/video.c fbdev-2.6/drivers/acpi/video.c
--- linus-2.6/drivers/acpi/video.c	2006-11-07 05:38:34.000000000 -0500
+++ fbdev-2.6/drivers/acpi/video.c	2006-12-06 05:01:22.000000000 -0500
@@ -30,6 +30,7 @@
 #include <linux/list.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include <linux/display.h> 
 
 #include <asm/uaccess.h>
 
@@ -154,6 +155,19 @@
 	int *levels;
 };
 
+ 
+#if defined(CONFIG_DISPLAY_DDC) || defined(CONFIG_DISPLAY_DDC_MODULE)
+static int acpi_display_get_power(struct display_device *dev)
+{
+	return 0;
+}
+
+static int acpi_display_set_power(struct display_device *dev)
+{
+	return 0;
+}
+#endif
+
 struct acpi_video_device {
 	unsigned long device_id;
 	struct acpi_video_device_flags flags;
@@ -162,6 +176,10 @@
 	struct acpi_video_bus *video;
 	struct acpi_device *dev;
 	struct acpi_video_device_brightness *brightness;
+#if defined(CONFIG_DISPLAY_DDC) || defined(CONFIG_DISPLAY_DDC_MODULE)
+	struct display_driver acpi_display_driver;
+	struct display_device *display;
+#endif
 };
 
 /* bus */
@@ -399,6 +417,24 @@
 	return status;
 }
 
+#if defined(CONFIG_DISPLAY_DDC) || defined(CONFIG_DISPLAY_DDC_MODULE)
+static void *acpi_display_get_EDID(struct acpi_video_device *dev)
+{
+	union acpi_object *edid = NULL;
+	void *data = NULL;
+	int status;
+
+	status = acpi_video_device_EDID(dev, &edid, 128);
+	if (ACPI_FAILURE(status))
+		status = acpi_video_device_EDID(dev, &edid, 256);
+
+	if (ACPI_SUCCESS(status))
+		if (edid && edid->type == ACPI_TYPE_BUFFER)
+			data = edid->buffer.pointer;
+	return data;
+}
+#endif
+
 /* bus */
 
 static int
@@ -1255,7 +1291,6 @@
 	int status;
 	struct acpi_video_device *data;
 
-
 	if (!device || !video)
 		return -EINVAL;
 
@@ -1263,12 +1298,10 @@
 	    acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
 	if (ACPI_SUCCESS(status)) {
 
-		data = kmalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
+		data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
 		if (!data)
 			return -ENOMEM;
 
-		memset(data, 0, sizeof(struct acpi_video_device));
-
 		strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
 		strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
 		acpi_driver_data(device) = data;
@@ -1295,6 +1328,13 @@
 		acpi_video_device_bind(video, data);
 		acpi_video_device_find_cap(data);
 
+#if defined(CONFIG_DISPLAY_DDC) || defined(CONFIG_DISPLAY_DDC_MODULE)
+		data->acpi_display_driver.get_power = acpi_display_get_power;
+		data->acpi_display_driver.set_power = acpi_display_set_power;
+		data->acpi_display_driver.probe = probe_edid;
+		data->display = display_device_register(&data->acpi_display_driver,
+						NULL, acpi_display_get_EDID(data));
+#endif
 		status = acpi_install_notify_handler(device->handle,
 						     ACPI_DEVICE_NOTIFY,
 						     acpi_video_device_notify,
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/macintosh/Kconfig fbdev-2.6/drivers/macintosh/Kconfig
--- linus-2.6/drivers/macintosh/Kconfig	2006-12-05 05:07:18.000000000 -0500
+++ fbdev-2.6/drivers/macintosh/Kconfig	2006-12-06 05:01:22.000000000 -0500
@@ -123,7 +123,7 @@
 config PMAC_BACKLIGHT
 	bool "Backlight control for LCD screens"
 	depends on ADB_PMU && FB = y && (BROKEN || !PPC64)
-	select FB_BACKLIGHT
+	select BACKLIGHT_CLASS_DEVICE
 	help
 	  Say Y here to enable Macintosh specific extensions of the generic
 	  backlight code. With this enabled, the brightness keys on older
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/display-ddc.c fbdev-2.6/drivers/video/display/display-ddc.c
--- linus-2.6/drivers/video/display/display-ddc.c	1969-12-31 19:00:00.000000000 -0500
+++ fbdev-2.6/drivers/video/display/display-ddc.c	2006-12-06 04:31:24.000000000 -0500
@@ -0,0 +1,49 @@
+/*
+ *  display-ddc.c - EDID parsing code
+ *
+ *  Copyright (C) 2006 James Simmons <jsimmons@infradead.org>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/module.h>
+#include <linux/display.h>
+#include <linux/err.h>
+#include <linux/ctype.h>
+
+#include <linux/fb.h>
+
+int probe_edid(struct display_device *dev, void *data)
+{
+	struct fb_monspecs spec;
+	ssize_t size;
+
+	if (!data)
+		return 0;
+	size = sizeof(spec.manufacturer) + sizeof(spec.monitor) + sizeof(spec.ascii);
+	dev->name = kzalloc(size, GFP_KERNEL);
+	fb_edid_to_monspecs((unsigned char *) data, &spec);
+	strcpy(dev->name, spec.manufacturer);
+	return snprintf(dev->name, size, "%s %s %s\n", spec.manufacturer,
+			spec.monitor, spec.ascii);
+}
+EXPORT_SYMBOL(probe_edid);
+
+MODULE_DESCRIPTION("Display Hardware handling");
+MODULE_AUTHOR("James Simmons <jsimmons@infradead.org>");
+MODULE_LICENSE("GPL");
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/display-sysfs.c fbdev-2.6/drivers/video/display/display-sysfs.c
--- linus-2.6/drivers/video/display/display-sysfs.c	1969-12-31 19:00:00.000000000 -0500
+++ fbdev-2.6/drivers/video/display/display-sysfs.c	2006-12-06 04:32:15.000000000 -0500
@@ -0,0 +1,161 @@
+/*
+ *  display.c - Display output driver
+ *
+ *  Copyright (C) 2006 James Simmons <jsimmons@infradead.org>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/module.h>
+#include <linux/display.h>
+#include <linux/err.h>
+#include <linux/ctype.h>
+
+static ssize_t display_show_name(struct class_device *dev, char *buf)
+{
+	struct display_device *dsp = to_display_device(dev);
+	return snprintf(buf, PAGE_SIZE, "%s\n", dsp->name);
+}
+
+static ssize_t display_show_power(struct class_device *dev, char *buf)
+{
+	struct display_device *dsp = to_display_device(dev);
+	ssize_t ret = -ENXIO;
+
+	mutex_lock(&dsp->lock);
+	if (likely(dsp->driver->get_power))
+		ret = sprintf(buf,"%.8x\n", dsp->driver->get_power(dsp));
+	mutex_unlock(&dsp->lock);
+	return ret;
+}
+
+static ssize_t display_store_power(struct class_device *dev,
+	const char *buf,size_t count)
+{
+	struct display_device *dsp = to_display_device(dev);
+	size_t size;
+	char *endp;
+	int power;
+
+	power = simple_strtoul(buf, &endp, 0);
+	size = endp - buf;
+	if (*endp && isspace(*endp))
+		size++;
+	if (size != count)
+		return -EINVAL;
+
+	mutex_lock(&dsp->lock);
+	if (likely(dsp->driver->set_power)) {
+		dsp->request_state = power;
+		dsp->driver->set_power(dsp);
+	}
+	mutex_unlock(&dsp->lock);
+	return count;
+}
+
+static void display_class_release(struct class_device *dev)
+{
+	struct display_device *dsp = to_display_device(dev);
+	kfree(dsp);
+}
+
+static struct class_device_attribute display_attributes[] = {
+	__ATTR(name, S_IRUGO, display_show_name, NULL),
+	__ATTR(power, S_IRUGO | S_IWUSR, display_show_power, display_store_power),
+};
+
+static struct class display_class = {
+	.name = "display",
+	.release = display_class_release,
+	.class_dev_attrs = display_attributes,
+};
+
+static int index;
+
+struct display_device *display_device_register(struct display_driver *driver,
+						struct device *dev, void *devdata)
+{
+	struct display_device *new_dev;
+	int ret = -ENOMEM, i;
+
+	if (unlikely(!driver))
+		return ERR_PTR(-EINVAL);
+
+	new_dev = kzalloc(sizeof(struct display_device), GFP_KERNEL);
+	if (likely(new_dev) && unlikely(driver->probe(new_dev, devdata))) {
+		mutex_init(&new_dev->lock);
+		new_dev->driver = driver;
+		new_dev->class_dev.class = &display_class;
+		new_dev->class_dev.dev = dev;
+		sprintf(new_dev->class_dev.class_id, "display%d", index++);
+		class_set_devdata(&new_dev->class_dev, devdata);
+		ret = class_device_register(&new_dev->class_dev);
+
+		if (likely(ret)) {
+			for (i = 0; i < ARRAY_SIZE(display_attributes); i++) {
+				ret = class_device_create_file(&new_dev->class_dev,
+							&display_attributes[i]);
+				if (unlikely(ret)) {
+					while (--i >= 0)
+						class_device_remove_file(&new_dev->class_dev,
+							&display_attributes[i]);
+					class_device_unregister(&new_dev->class_dev);
+				}
+			}
+		}
+	}
+	if (unlikely(ret)) {
+		kfree(new_dev);
+		new_dev = ERR_PTR(ret);
+	}
+	return new_dev;
+}
+EXPORT_SYMBOL(display_device_register);
+
+void display_device_unregister(struct display_device *dev)
+{
+	int i;
+
+	if (!dev)
+		return;
+	mutex_lock(&dev->lock);
+	dev->driver = NULL;
+	for (i = 0; i < ARRAY_SIZE(display_attributes); i++)
+		class_device_remove_file(&dev->class_dev,
+					&display_attributes[i]);
+	mutex_unlock(&dev->lock);
+	class_device_unregister(&dev->class_dev);
+}
+EXPORT_SYMBOL(display_device_unregister);
+
+static void __exit display_class_exit(void)
+{
+	class_unregister(&display_class);
+}
+
+static int __init display_class_init(void)
+{
+	return class_register(&display_class);
+}
+
+postcore_initcall(display_class_init);
+module_exit(display_class_exit);
+
+MODULE_DESCRIPTION("Display Hardware handling");
+MODULE_AUTHOR("James Simmons <jsimmons@infradead.org>");
+MODULE_LICENSE("GPL");
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/Kconfig fbdev-2.6/drivers/video/display/Kconfig
--- linus-2.6/drivers/video/display/Kconfig	1969-12-31 19:00:00.000000000 -0500
+++ fbdev-2.6/drivers/video/display/Kconfig	2006-12-06 04:50:40.000000000 -0500
@@ -0,0 +1,29 @@
+#
+# Display drivers configuration
+#
+
+menu "Display device support"
+
+config DISPLAY_SUPPORT
+	tristate "Display panel/monitor support"
+	---help---
+	  This framework adds support for low-level control of a display. 
+	  This includes support for power.
+
+	  Enable this to be able to choose the drivers for controlling the
+	  physical display panel/monitor on some platforms. This not only
+	  covers LCD displays for PDAs but also other types of displays
+	  such as CRT, TVout etc.
+
+	  To have support for your specific display panel you will have to
+	  select the proper drivers which depend on this option.
+
+config DISPLAY_DDC
+	tristate "Enable EDID parsing"
+	---help---
+	  Enable EDID parsing
+
+comment "Display hardware drivers"
+	depends on DISPLAY_SUPPORT
+
+endmenu
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/Makefile fbdev-2.6/drivers/video/display/Makefile
--- linus-2.6/drivers/video/display/Makefile	1969-12-31 19:00:00.000000000 -0500
+++ fbdev-2.6/drivers/video/display/Makefile	2006-12-06 04:54:08.000000000 -0500
@@ -0,0 +1,7 @@
+# Display drivers
+
+display-objs				:= display-sysfs.o 
+
+obj-$(CONFIG_DISPLAY_SUPPORT)		+= display.o
+
+obj-$(CONFIG_DISPLAY_DDC)		+= display-ddc.o
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/Kconfig fbdev-2.6/drivers/video/Kconfig
--- linus-2.6/drivers/video/Kconfig	2006-11-30 05:06:13.000000000 -0500
+++ fbdev-2.6/drivers/video/Kconfig	2006-12-06 05:01:22.000000000 -0500
@@ -4,20 +4,10 @@
 
 menu "Graphics support"
 
-config FIRMWARE_EDID
-       bool "Enable firmware EDID"
-       default y
-       ---help---
-         This enables access to the EDID transferred from the firmware.
-	 On the i386, this is from the Video BIOS. Enable this if DDC/I2C
-	 transfers do not work for your driver and if you are using
-	 nvidiafb, i810fb or savagefb.
-
-	 In general, choosing Y for this option is safe.  If you
-	 experience extremely long delays while booting before you get
-	 something on your display, try setting this to N.  Matrox cards in
-	 combination with certain motherboards and monitors are known to
-	 suffer from this problem.
+if SYSFS
+	source "drivers/video/backlight/Kconfig"
+	source "drivers/video/display/Kconfig"
+endif
 
 config FB
 	tristate "Support for frame buffer devices"
@@ -53,6 +43,22 @@
 	  (e.g. an accelerated X server) and that are not frame buffer
 	  device-aware may cause unexpected results. If unsure, say N.
 
+config FIRMWARE_EDID
+       bool "Enable firmware EDID"
+       depends on FB
+       default n 
+       ---help---
+         This enables access to the EDID transferred from the firmware.
+	 On the i386, this is from the Video BIOS. Enable this if DDC/I2C
+	 transfers do not work for your driver and if you are using
+	 nvidiafb, i810fb or savagefb.
+
+	 In general, choosing Y for this option is safe.  If you
+	 experience extremely long delays while booting before you get
+	 something on your display, try setting this to N.  Matrox cards in
+	 combination with certain motherboards and monitors are known to
+	 suffer from this problem.
+
 config FB_DDC
        tristate
        depends on FB && I2C && I2C_ALGOBIT
@@ -90,13 +96,6 @@
        depends on FB
        default n
 
-config FB_BACKLIGHT
-	bool
-	depends on FB
-	select BACKLIGHT_LCD_SUPPORT
-	select BACKLIGHT_CLASS_DEVICE
-	default n
-
 config FB_MODE_HELPERS
         bool "Enable Video Mode Handling Helpers"
         depends on FB
@@ -126,6 +125,9 @@
 	 This is particularly important to one driver, matroxfb.  If
 	 unsure, say N.
 
+comment "Frambuffer hardware drivers"
+	depends on FB
+
 config FB_CIRRUS
 	tristate "Cirrus Logic support"
 	depends on FB && (ZORRO || PCI)
@@ -551,6 +553,7 @@
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
+	select VIDEO_SELECT
 	help
 	  This is the frame buffer device driver for generic VESA 2.0
 	  compliant graphic cards. The older VESA 1.2 cards are not supported.
@@ -728,8 +731,7 @@
 
 config FB_NVIDIA_BACKLIGHT
 	bool "Support for backlight control"
-	depends on FB_NVIDIA && PMAC_BACKLIGHT
-	select FB_BACKLIGHT
+	depends on FB_NVIDIA && BACKLIGHT_CLASS_DEVICE
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -775,8 +777,7 @@
 
 config FB_RIVA_BACKLIGHT
 	bool "Support for backlight control"
-	depends on FB_RIVA && PMAC_BACKLIGHT
-	select FB_BACKLIGHT
+	depends on FB_RIVA && BACKLIGHT_CLASS_DEVICE
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -1049,8 +1050,7 @@
 
 config FB_RADEON_BACKLIGHT
 	bool "Support for backlight control"
-	depends on FB_RADEON && PMAC_BACKLIGHT
-	select FB_BACKLIGHT
+	depends on FB_RADEON && BACKLIGHT_CLASS_DEVICE 
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -1081,8 +1081,7 @@
 
 config FB_ATY128_BACKLIGHT
 	bool "Support for backlight control"
-	depends on FB_ATY128 && PMAC_BACKLIGHT
-	select FB_BACKLIGHT
+	depends on FB_ATY128 && BACKLIGHT_CLASS_DEVICE 
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -1131,8 +1130,7 @@
 
 config FB_ATY_BACKLIGHT
 	bool "Support for backlight control"
-	depends on FB_ATY && PMAC_BACKLIGHT
-	select FB_BACKLIGHT
+	depends on FB_ATY && BACKLIGHT_CLASS_DEVICE 
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -1632,6 +1630,7 @@
 	  the vfb_enable=1 option.
 
 	  If unsure, say N.
+
 if VT
 	source "drivers/video/console/Kconfig"
 endif
@@ -1640,9 +1639,5 @@
 	source "drivers/video/logo/Kconfig"
 endif
 
-if SYSFS
-	source "drivers/video/backlight/Kconfig"
-endif
-
 endmenu
 
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/Makefile fbdev-2.6/drivers/video/Makefile
--- linus-2.6/drivers/video/Makefile	2006-11-07 05:38:36.000000000 -0500
+++ fbdev-2.6/drivers/video/Makefile	2006-12-06 05:01:22.000000000 -0500
@@ -12,7 +12,7 @@
 
 obj-$(CONFIG_VT)		  += console/
 obj-$(CONFIG_LOGO)		  += logo/
-obj-$(CONFIG_SYSFS)		  += backlight/
+obj-$(CONFIG_SYSFS)		  += backlight/ display/
 
 obj-$(CONFIG_FB_CFB_FILLRECT)  += cfbfillrect.o
 obj-$(CONFIG_FB_CFB_COPYAREA)  += cfbcopyarea.o
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/include/linux/display.h fbdev-2.6/include/linux/display.h
--- linus-2.6/include/linux/display.h	1969-12-31 19:00:00.000000000 -0500
+++ fbdev-2.6/include/linux/display.h	2006-12-05 14:43:54.000000000 -0500
@@ -0,0 +1,55 @@
+/*
+ *  Copyright (C) 2006 James Simmons <jsimmons@infradead.org>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#ifndef _LINUX_DISPLAY_H
+#define _LINUX_DISPLAY_H
+
+#include <linux/device.h>
+
+struct display_device;
+
+/* This structure defines all the properties of a Display. */
+struct display_driver {
+	int (*set_power)(struct display_device *);
+	int (*get_power)(struct display_device *);
+	int (*probe)(struct display_device *, void *);
+	int (*remove)(struct display_device *);
+};
+
+struct display_device {
+	struct module *owner;	/* Owner module */
+	char *name;
+	struct mutex lock;	
+	int request_state;
+	struct display_driver *driver;
+	struct class_device class_dev;		/* The class device structure */
+};
+
+extern struct display_device *display_device_register(struct display_driver *driver,
+					struct device *dev, void *devdata);
+extern void display_device_unregister(struct display_device *dev);
+
+extern int probe_edid(struct display_device *dev, void *devdata);
+
+#define to_display_device(obj) container_of(obj, struct display_device, class_dev)
+
+#endif

Re: Display class

[Miguel Ojeda]

On 12/5/06, James Simmons <jsimmons@infradead.org> wrote:
>
> This is the pass at a display class to meet the needs of the output class
> of Mr. Yu for acpi. Also this class could in time replace the lcd class
> located in the backlight directory since a lcd is a type of display.
> The final hope is that the purpose auxdisplay could fall under this
> catergory.
>
> P.S
>    I know the edid parsing would have to be pulled out of the fbdev layer.
>

Few comments about EXPORT_SYMBOL_GPL:

>
> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/acpi/video.c fbdev-2.6/drivers/acpi/video.c
> --- linus-2.6/drivers/acpi/video.c      2006-11-07 05:38:34.000000000 -0500
> +++ fbdev-2.6/drivers/acpi/video.c      2006-12-04 10:40:48.000000000 -0500
> @@ -30,6 +30,9 @@
>  #include <linux/list.h>
>  #include <linux/proc_fs.h>
>  #include <linux/seq_file.h>
> +#if defined(CONFIG_DISPLAY_DDC)
> +#include <linux/display.h>
> +#endif
>
>  #include <asm/uaccess.h>
>
> @@ -154,6 +157,20 @@
>         int *levels;
>  };
>
> +#if defined(CONFIG_DISPLAY_DDC)
> +static int
> +acpi_display_get_power(struct display_device *dev)
> +{
> +       return 0;
> +}
> +
> +static int
> +acpi_display_set_power(struct display_device *dev)
> +{
> +       return 0;
> +}
> +#endif
> +
>  struct acpi_video_device {
>         unsigned long device_id;
>         struct acpi_video_device_flags flags;
> @@ -162,6 +179,10 @@
>         struct acpi_video_bus *video;
>         struct acpi_device *dev;
>         struct acpi_video_device_brightness *brightness;
> +#if defined(CONFIG_DISPLAY_DDC)
> +       struct display_properties acpi_display_properties;
> +       struct display_device *display;
> +#endif
>  };
>
>  /* bus */
> @@ -399,6 +420,27 @@
>         return status;
>  }
>
> +#if defined(CONFIG_DISPLAY_DDC)
> +static void*
> +acpi_display_get_EDID(struct acpi_video_device *dev)
> +{
> +       union acpi_object *edid = NULL;
> +       void *data = NULL;
> +       int status;
> +
> +       status = acpi_video_device_EDID(dev, &edid, 128);
> +       if (ACPI_FAILURE(status))
> +               status = acpi_video_device_EDID(dev, &edid, 256);
> +
> +       if (ACPI_SUCCESS(status)) {
> +               if (edid && edid->type == ACPI_TYPE_BUFFER) {
> +                       data = edid->buffer.pointer;
> +               }
> +       }
> +       return data;
> +}
> +#endif
> +
>  /* bus */
>
>  static int
> @@ -1255,7 +1297,6 @@
>         int status;
>         struct acpi_video_device *data;
>
> -
>         if (!device || !video)
>                 return -EINVAL;
>
> @@ -1263,12 +1304,10 @@
>             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
>         if (ACPI_SUCCESS(status)) {
>
> -               data = kmalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
> +               data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
>                 if (!data)
>                         return -ENOMEM;
>
> -               memset(data, 0, sizeof(struct acpi_video_device));
> -
>                 strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
>                 strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
>                 acpi_driver_data(device) = data;
> @@ -1295,6 +1334,13 @@
>                 acpi_video_device_bind(video, data);
>                 acpi_video_device_find_cap(data);
>
> +#ifdef CONFIG_DISPLAY_DDC
> +               data->acpi_display_properties.get_power = acpi_display_get_power;
> +               data->acpi_display_properties.set_power = acpi_display_set_power;
> +               data->acpi_display_properties.probe = probe_edid;
> +               data->display = display_device_register(NULL, acpi_display_get_EDID(data),
> +                                                       &data->acpi_display_properties);
> +#endif
>                 status = acpi_install_notify_handler(device->handle,
>                                                      ACPI_DEVICE_NOTIFY,
>                                                      acpi_video_device_notify,
> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/display-ddc.c fbdev-2.6/drivers/video/display/display-ddc.c
> --- linus-2.6/drivers/video/display/display-ddc.c       1969-12-31 19:00:00.000000000 -0500
> +++ fbdev-2.6/drivers/video/display/display-ddc.c       2006-12-03 05:27:00.000000000 -0500
> @@ -0,0 +1,45 @@
> +/*
> + *  display-ddc.c - EDID paring code
> + *
> + *  Copyright (C) 2006 James Simmons <jsimmons@infradead.org>
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; either version 2 of the License, or (at
> + *  your option) any later version.
> + *
> + *  This program is distributed in the hope that it will be useful, but
> + *  WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + *  General Public License for more details.
> + *
> + *  You should have received a copy of the GNU General Public License along
> + *  with this program; if not, write to the Free Software Foundation, Inc.,
> + *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + */
> +#include <linux/module.h>
> +#include <linux/display.h>
> +#include <linux/err.h>
> +#include <linux/ctype.h>
> +
> +#include <linux/fb.h>
> +
> +int probe_edid(struct display_device *dev, void *data)
> +{
> +       struct fb_monspecs spec;
> +       ssize_t size = 45;
> +
> +       dev->name = kzalloc(size, GFP_KERNEL);
> +       fb_edid_to_monspecs((unsigned char *) data, &spec);
> +       strcpy(dev->name, spec.manufacturer);
> +       return snprintf(dev->name, size, "%s %s %s\n", spec.manufacturer, spec.monitor, spec.ascii);
> +}
> +EXPORT_SYMBOL(probe_edid);

Shouldn't be EXPORT_SYMBOL_GPL?

> +
> +MODULE_DESCRIPTION("Display Hardware handling");
> +MODULE_AUTHOR("James Simmons <jsimmons@infradead.org>");
> +MODULE_LICENSE("GPL");
> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/display-sysfs.c fbdev-2.6/drivers/video/display/display-sysfs.c
> --- linus-2.6/drivers/video/display/display-sysfs.c     1969-12-31 19:00:00.000000000 -0500
> +++ fbdev-2.6/drivers/video/display/display-sysfs.c     2006-12-04 07:48:34.000000000 -0500
> @@ -0,0 +1,164 @@
> +/*
> + *  display.c - Display output driver
> + *
> + *  Copyright (C) 2006 James Simmons <jsimmons@infradead.org>
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; either version 2 of the License, or (at
> + *  your option) any later version.
> + *
> + *  This program is distributed in the hope that it will be useful, but
> + *  WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + *  General Public License for more details.
> + *
> + *  You should have received a copy of the GNU General Public License along
> + *  with this program; if not, write to the Free Software Foundation, Inc.,
> + *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + */
> +#include <linux/module.h>
> +#include <linux/display.h>
> +#include <linux/err.h>
> +#include <linux/ctype.h>
> +
> +static ssize_t display_show_name(struct class_device *dev, char *buf)
> +{
> +       struct display_device *dsp = to_display_device(dev);
> +       return snprintf(buf, PAGE_SIZE, "%s\n", dsp->name);
> +}
> +
> +static ssize_t display_show_power(struct class_device *dev, char *buf)
> +{
> +       struct display_device *dsp = to_display_device(dev);
> +       ssize_t ret = -ENXIO;
> +
> +       mutex_lock(&dsp->lock);
> +       if (likely(dsp->driver->get_power))
> +               ret = sprintf(buf,"%.8x\n", dsp->driver->get_power(dsp));
> +       mutex_unlock(&dsp->lock);
> +       return ret;
> +}
> +
> +static ssize_t display_store_power(struct class_device *dev,
> +       const char *buf,size_t count)
> +{
> +       struct display_device *dsp = to_display_device(dev);
> +       size_t size;
> +       char *endp;
> +       int power;
> +
> +       power = simple_strtoul(buf, &endp, 0);
> +       size = endp - buf;
> +       if (*endp && isspace(*endp))
> +               size++;
> +       if (size != count)
> +               return -EINVAL;
> +
> +       mutex_lock(&dsp->lock);
> +       if (likely(dsp->driver->set_power)) {
> +               dsp->request_state = power;
> +               dsp->driver->set_power(dsp);
> +       }
> +       mutex_unlock(&dsp->lock);
> +       return count;
> +}
> +
> +static void display_class_release(struct class_device *dev)
> +{
> +       struct display_device *dsp = to_display_device(dev);
> +       kfree(dsp);
> +}
> +
> +static struct class_device_attribute display_attributes[] = {
> +       __ATTR(name, S_IRUGO, display_show_name, NULL),
> +       __ATTR(power, S_IRUGO | S_IWUSR, display_show_power, display_store_power),
> +};
> +
> +static struct class display_class = {
> +       .name = "display",
> +       .release = display_class_release,
> +       .class_dev_attrs = display_attributes,
> +};
> +
> +static int index;
> +
> +struct display_device *display_device_register(struct display_driver *driver,
> +                                               struct device *dev, void *devdata)
> +{
> +       struct display_device *new_dev;
> +       int ret = -ENOMEM, i;
> +
> +       if (unlikely(!driver))
> +               return ERR_PTR(-EINVAL);
> +
> +       new_dev = kzalloc(sizeof(struct display_device), GFP_KERNEL);
> +       if (likely(new_dev)) {
> +               driver->probe(new_dev, devdata);
> +
> +               mutex_init(&new_dev->lock);
> +               new_dev->driver = driver;
> +               new_dev->class_dev.class = &display_class;
> +               new_dev->class_dev.dev = dev;
> +               sprintf(new_dev->class_dev.class_id, "display%d", index++);
> +               class_set_devdata(&new_dev->class_dev, devdata);
> +               ret = class_device_register(&new_dev->class_dev);
> +
> +               if (likely(ret)) {
> +                       for (i = 0; i < ARRAY_SIZE(display_attributes); i++) {
> +                               ret = class_device_create_file(&new_dev->class_dev,
> +                                                               &display_attributes[i]);
> +                               if (unlikely(ret)) {
> +                                       while (--i >= 0)
> +                                               class_device_remove_file(&new_dev->class_dev,
> +                                                               &display_attributes[i]);
> +                                       class_device_unregister(&new_dev->class_dev);
> +                               }
> +                       }
> +               }
> +       }
> +       if (unlikely(ret)) {
> +               printk("failed to register display device\n");
> +               kfree(new_dev);
> +               new_dev = ERR_PTR(ret);
> +       }
> +       return new_dev;
> +}
> +EXPORT_SYMBOL(display_device_register);

Shouldn't be EXPORT_SYMBOL_GPL?

> +
> +void display_device_unregister(struct display_device *dev)
> +{
> +       int i;
> +
> +       if (!dev)
> +               return;
> +       mutex_lock(&dev->lock);
> +       dev->driver = NULL;
> +       for (i = 0; i < ARRAY_SIZE(display_attributes); i++)
> +               class_device_remove_file(&dev->class_dev,
> +                                       &display_attributes[i]);
> +       mutex_unlock(&dev->lock);
> +       class_device_unregister(&dev->class_dev);
> +}
> +EXPORT_SYMBOL(display_device_unregister);

Shouldn't be EXPORT_SYMBOL_GPL?

> +
> +static void __exit display_class_exit(void)
> +{
> +       class_unregister(&display_class);
> +}
> +
> +static int __init display_class_init(void)
> +{
> +       return class_register(&display_class);
> +}
> +
> +postcore_initcall(display_class_init);
> +module_exit(display_class_exit);
> +
> +MODULE_DESCRIPTION("Display Hardware handling");
> +MODULE_AUTHOR("James Simmons <jsimmons@infradead.org>");
> +MODULE_LICENSE("GPL");
> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/Kconfig fbdev-2.6/drivers/video/display/Kconfig
> --- linus-2.6/drivers/video/display/Kconfig     1969-12-31 19:00:00.000000000 -0500
> +++ fbdev-2.6/drivers/video/display/Kconfig     2006-12-04 11:41:03.000000000 -0500
> @@ -0,0 +1,29 @@
> +#
> +# Display drivers configuration
> +#
> +
> +menu "Display device support"
> +
> +config DISPLAY_SUPPORT
> +       tristate "Display panel/monitor support"
> +       ---help---
> +         This framework adds support for low-level control of a display.
> +         This includes support for power.
> +
> +         Enable this to be able to choose the drivers for controlling the
> +         physical display panel/monitor on some platforms. This not only
> +         covers LCD displays for PDAs but also other types of displays
> +         such as CRT, TVout etc.
> +
> +         To have support for your specific display panel you will have to
> +         select the proper drivers which depend on this option.
> +
> +config DISPLAY_DDC
> +       tristate "Enable EDID parsing"
> +       ---help---
> +         Enable EDID parsing
> +
> +comment "Display hardware drivers"
> +       depends on DISPLAY_SUPPORT
> +
> +endmenu
> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/Makefile fbdev-2.6/drivers/video/display/Makefile
> --- linus-2.6/drivers/video/display/Makefile    1969-12-31 19:00:00.000000000 -0500
> +++ fbdev-2.6/drivers/video/display/Makefile    2006-12-03 05:02:07.000000000 -0500
> @@ -0,0 +1,7 @@
> +# Display drivers
> +
> +display-objs                           := display-sysfs.o
> +
> +obj-$(CONFIG_DISPLAY_SUPPORT)          += display.o
> +
> +obj-$(CONFIG_DISPLAY_DDC)              += display-ddc.o
> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/Kconfig fbdev-2.6/drivers/video/Kconfig
> --- linus-2.6/drivers/video/Kconfig     2006-11-30 05:06:13.000000000 -0500
> +++ fbdev-2.6/drivers/video/Kconfig     2006-12-04 10:40:48.000000000 -0500
> @@ -4,21 +4,6 @@
>
>  menu "Graphics support"
>
> -config FIRMWARE_EDID
> -       bool "Enable firmware EDID"
> -       default y
> -       ---help---
> -         This enables access to the EDID transferred from the firmware.
> -        On the i386, this is from the Video BIOS. Enable this if DDC/I2C
> -        transfers do not work for your driver and if you are using
> -        nvidiafb, i810fb or savagefb.
> -
> -        In general, choosing Y for this option is safe.  If you
> -        experience extremely long delays while booting before you get
> -        something on your display, try setting this to N.  Matrox cards in
> -        combination with certain motherboards and monitors are known to
> -        suffer from this problem.
> -
>  config FB
>         tristate "Support for frame buffer devices"
>         ---help---
> @@ -53,6 +38,22 @@
>           (e.g. an accelerated X server) and that are not frame buffer
>           device-aware may cause unexpected results. If unsure, say N.
>
> +config FIRMWARE_EDID
> +       bool "Enable firmware EDID"
> +       depends on FB
> +       default n
> +       ---help---
> +         This enables access to the EDID transferred from the firmware.
> +        On the i386, this is from the Video BIOS. Enable this if DDC/I2C
> +        transfers do not work for your driver and if you are using
> +        nvidiafb, i810fb or savagefb.
> +
> +        In general, choosing Y for this option is safe.  If you
> +        experience extremely long delays while booting before you get
> +        something on your display, try setting this to N.  Matrox cards in
> +        combination with certain motherboards and monitors are known to
> +        suffer from this problem.
> +
>  config FB_DDC
>         tristate
>         depends on FB && I2C && I2C_ALGOBIT
> @@ -126,6 +127,9 @@
>          This is particularly important to one driver, matroxfb.  If
>          unsure, say N.
>
> +comment "Frambuffer hardware drivers"
> +       depends on FB
> +
>  config FB_CIRRUS
>         tristate "Cirrus Logic support"
>         depends on FB && (ZORRO || PCI)
> @@ -1641,6 +1647,7 @@
>  endif
>
>  if SYSFS
> +       source "drivers/video/display/Kconfig"
>         source "drivers/video/backlight/Kconfig"
>  endif
>
> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/Makefile fbdev-2.6/drivers/video/Makefile
> --- linus-2.6/drivers/video/Makefile    2006-11-07 05:38:36.000000000 -0500
> +++ fbdev-2.6/drivers/video/Makefile    2006-12-04 10:40:48.000000000 -0500
> @@ -12,7 +12,7 @@
>
>  obj-$(CONFIG_VT)                 += console/
>  obj-$(CONFIG_LOGO)               += logo/
> -obj-$(CONFIG_SYSFS)              += backlight/
> +obj-$(CONFIG_SYSFS)              += backlight/ display/
>
>  obj-$(CONFIG_FB_CFB_FILLRECT)  += cfbfillrect.o
>  obj-$(CONFIG_FB_CFB_COPYAREA)  += cfbcopyarea.o
> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/include/linux/display.h fbdev-2.6/include/linux/display.h
> --- linus-2.6/include/linux/display.h   1969-12-31 19:00:00.000000000 -0500
> +++ fbdev-2.6/include/linux/display.h   2006-12-04 07:42:29.000000000 -0500
> @@ -0,0 +1,55 @@
> +/*
> + *  Copyright (C) 2006 James Simmons <jsimmons@infradead.org>
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; either version 2 of the License, or (at
> + *  your option) any later version.
> + *
> + *  This program is distributed in the hope that it will be useful, but
> + *  WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + *  General Public License for more details.
> + *
> + *  You should have received a copy of the GNU General Public License along
> + *  with this program; if not, write to the Free Software Foundation, Inc.,
> + *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + */
> +
> +#ifndef _LINUX_DISPLAY_H
> +#define _LINUX_DISPLAY_H
> +
> +#include <linux/device.h>
> +
> +struct display_device;
> +
> +/* This structure defines all the properties of a Display. */
> +struct display_driver {
> +       int (*set_power)(struct display_device *);
> +       int (*get_power)(struct display_device *);
> +       int (*probe)(struct display_device *, void *);
> +       int (*remove)(struct display_device *);
> +};
> +
> +struct display_device {
> +       struct module *owner;   /* Owner module */
> +       char *name;
> +       struct mutex lock;
> +       int request_state;
> +       struct display_driver *driver;
> +       struct class_device class_dev;          /* The class device structure */
> +};
> +
> +extern struct display_device *display_device_register(struct display_driver *driver,
> +                                       struct device *dev, void *devdata);
> +extern void display_device_unregister(struct display_device *dev);
> +
> +extern int probe_edid(struct display_device *dev, void *devdata);
> +
> +#define to_display_device(obj) container_of(obj, struct display_device, class_dev)
> +
> +#endif
> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/MAINTAINERS fbdev-2.6/MAINTAINERS
> --- linus-2.6/MAINTAINERS       2006-12-04 04:11:38.000000000 -0500
> +++ fbdev-2.6/MAINTAINERS       2006-12-04 10:40:48.000000000 -0500
> @@ -911,6 +923,12 @@
>  L:     linux-kernel@vger.kernel.org
>  S:     Maintained
>
> +DISPLAY SUBSYSTEM
> +P:     James Simmons
> +M:     jsimmons@infradead.org
> +L:     linux-kernel@vger.kernel.org
> +S:     Maintained
> +
>  DISTRIBUTED LOCK MANAGER
>  P:     Patrick Caulfield
>  M:     pcaulfie@redhat.com
>


-- 
Miguel Ojeda
http://maxextreme.googlepages.com/index.htm

Re: Display class

[Randy Dunlap]

On Tue, 5 Dec 2006 18:03:39 +0000 (GMT) James Simmons wrote:

> This is the pass at a display class to meet the needs of the output class 
> of Mr. Yu for acpi. Also this class could in time replace the lcd class 
> located in the backlight directory since a lcd is a type of display.
> The final hope is that the purpose auxdisplay could fall under this 
> catergory.
> 
> P.S
>    I know the edid parsing would have to be pulled out of the fbdev layer.

Hi,

Where is "struct display_properties" defined?

  CC [M]  drivers/acpi/video.o
drivers/acpi/video.c:183: error: field 'acpi_display_properties' has incomplete type
make[2]: *** [drivers/acpi/video.o] Error 1

Lots of style issues (see below).

> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/acpi/video.c fbdev-2.6/drivers/acpi/video.c
> --- linus-2.6/drivers/acpi/video.c	2006-11-07 05:38:34.000000000 -0500
> +++ fbdev-2.6/drivers/acpi/video.c	2006-12-04 10:40:48.000000000 -0500
> @@ -30,6 +30,9 @@
>  #include <linux/list.h>
>  #include <linux/proc_fs.h>
>  #include <linux/seq_file.h>
> +#if defined(CONFIG_DISPLAY_DDC)
> +#include <linux/display.h> 
> +#endif
>  
>  #include <asm/uaccess.h>
>  
> @@ -154,6 +157,20 @@
>  	int *levels;
>  };
>  
> +#if defined(CONFIG_DISPLAY_DDC)
> +static int
> +acpi_display_get_power(struct display_device *dev)

Combine those 2 lines into 1 line.

> +{
> +	return 0;
> +}
> +
> +static int
> +acpi_display_set_power(struct display_device *dev)

Ditto.

> +{
> +	return 0;
> +}
> +#endif
> +
>  struct acpi_video_device {
>  	unsigned long device_id;
>  	struct acpi_video_device_flags flags;
> @@ -162,6 +179,10 @@
>  	struct acpi_video_bus *video;
>  	struct acpi_device *dev;
>  	struct acpi_video_device_brightness *brightness;
> +#if defined(CONFIG_DISPLAY_DDC)
> +	struct display_properties acpi_display_properties;
> +	struct display_device *display;
> +#endif
>  };
>  
>  /* bus */
> @@ -399,6 +420,27 @@
>  	return status;
>  }
>  
> +#if defined(CONFIG_DISPLAY_DDC)
> +static void*
> +acpi_display_get_EDID(struct acpi_video_device *dev)

Combine and place '*' immediately before the function name,
not immediately after "void".

> +{
> +	union acpi_object *edid = NULL;
> +	void *data = NULL;
> +	int status;
> +
> +	status = acpi_video_device_EDID(dev, &edid, 128);
> +	if (ACPI_FAILURE(status))
> +		status = acpi_video_device_EDID(dev, &edid, 256);
> +
> +	if (ACPI_SUCCESS(status)) {
> +		if (edid && edid->type == ACPI_TYPE_BUFFER) {
> +			data = edid->buffer.pointer;

No braces for one-statement "blocks".

> +		}
> +	}
> +	return data;
> +}
> +#endif
> +
>  /* bus */
>  
>  static int

> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/display-ddc.c fbdev-2.6/drivers/video/display/display-ddc.c
> --- linus-2.6/drivers/video/display/display-ddc.c	1969-12-31 19:00:00.000000000 -0500
> +++ fbdev-2.6/drivers/video/display/display-ddc.c	2006-12-03 05:27:00.000000000 -0500
> @@ -0,0 +1,45 @@
> +/*
> + *  display-ddc.c - EDID paring code

typo:  parsing

> +#include <linux/module.h>
> +#include <linux/display.h>
> +#include <linux/err.h>
> +#include <linux/ctype.h>
> +
> +#include <linux/fb.h>
> +
> +int probe_edid(struct display_device *dev, void *data)
> +{
> +	struct fb_monspecs spec;
> +	ssize_t size = 45;

Where does the magic # 45 come from?
Can you use a #define or sizeof(X) for it instead?

> +
> +	dev->name = kzalloc(size, GFP_KERNEL);
> +	fb_edid_to_monspecs((unsigned char *) data, &spec);
> +	strcpy(dev->name, spec.manufacturer);
> +	return snprintf(dev->name, size, "%s %s %s\n", spec.manufacturer, spec.monitor, spec.ascii);

Try to limit source lines to < 80 columns.

> +}
> +EXPORT_SYMBOL(probe_edid);
> +
> +MODULE_DESCRIPTION("Display Hardware handling");
> +MODULE_AUTHOR("James Simmons <jsimmons@infradead.org>");
> +MODULE_LICENSE("GPL");

> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/display-sysfs.c fbdev-2.6/drivers/video/display/display-sysfs.c
> --- linus-2.6/drivers/video/display/display-sysfs.c	1969-12-31 19:00:00.000000000 -0500
> +++ fbdev-2.6/drivers/video/display/display-sysfs.c	2006-12-04 07:48:34.000000000 -0500
> @@ -0,0 +1,164 @@
> +#include <linux/module.h>
> +#include <linux/display.h>
> +#include <linux/err.h>
> +#include <linux/ctype.h>
> +
> +struct display_device *display_device_register(struct display_driver *driver,
> +						struct device *dev, void *devdata)
> +{
> +	struct display_device *new_dev;
> +	int ret = -ENOMEM, i;
> +
> +	if (unlikely(!driver))
> +		return ERR_PTR(-EINVAL);
> +
> +	new_dev = kzalloc(sizeof(struct display_device), GFP_KERNEL);
> +	if (likely(new_dev)) {
> +		driver->probe(new_dev, devdata);
> +
> +		mutex_init(&new_dev->lock);
> +		new_dev->driver = driver;
> +		new_dev->class_dev.class = &display_class;
> +		new_dev->class_dev.dev = dev;
> +		sprintf(new_dev->class_dev.class_id, "display%d", index++);
> +		class_set_devdata(&new_dev->class_dev, devdata);
> +		ret = class_device_register(&new_dev->class_dev);
> +
> +		if (likely(ret)) {
> +			for (i = 0; i < ARRAY_SIZE(display_attributes); i++) {
> +				ret = class_device_create_file(&new_dev->class_dev,
> +								&display_attributes[i]);
> +				if (unlikely(ret)) {
> +					while (--i >= 0)
> +						class_device_remove_file(&new_dev->class_dev,
> +								&display_attributes[i]);
> +					class_device_unregister(&new_dev->class_dev);

Several lines > 80 columns there.

> +				}
> +			}
> +		}
> +	}
> +	if (unlikely(ret)) {
> +		printk("failed to register display device\n");

*			KERN_ERR or some such printk log level

> +		kfree(new_dev);
> +		new_dev = ERR_PTR(ret);
> +	}
> +	return new_dev;
> +}
> +EXPORT_SYMBOL(display_device_register);
> +
> +void display_device_unregister(struct display_device *dev)
> +{
> +	int i;
> +
> +	if (!dev)
> +		return;
> +	mutex_lock(&dev->lock);
> +	dev->driver = NULL;
> +	for (i = 0; i < ARRAY_SIZE(display_attributes); i++)
> +		class_device_remove_file(&dev->class_dev,
> +					&display_attributes[i]);
> +	mutex_unlock(&dev->lock);
> +	class_device_unregister(&dev->class_dev);
> +}
> +EXPORT_SYMBOL(display_device_unregister);
> +
> +static void __exit display_class_exit(void)
> +{
> +	class_unregister(&display_class);
> +}
> +
> +static int __init display_class_init(void)
> +{
> +	return class_register(&display_class);
> +}
> +
> +postcore_initcall(display_class_init);
> +module_exit(display_class_exit);
> +
> +MODULE_DESCRIPTION("Display Hardware handling");
> +MODULE_AUTHOR("James Simmons <jsimmons@infradead.org>");
> +MODULE_LICENSE("GPL");

> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/Kconfig fbdev-2.6/drivers/video/display/Kconfig
> --- linus-2.6/drivers/video/display/Kconfig	1969-12-31 19:00:00.000000000 -0500
> +++ fbdev-2.6/drivers/video/display/Kconfig	2006-12-04 11:41:03.000000000 -0500
> @@ -0,0 +1,29 @@
> +#
> +# Display drivers configuration
> +#
> +
> +menu "Display device support"
> +
> +config DISPLAY_SUPPORT
> +	tristate "Display panel/monitor support"
> +	---help---
> +	  This framework adds support for low-level control of a display. 
> +	  This includes support for power.
> +
> +	  Enable this to be able to choose the drivers for controlling the
> +	  physical display panel/monitor on some platforms. This not only
> +	  covers LCD displays for PDAs but also other types of displays
> +	  such as CRT, TVout etc.
> +
> +	  To have support for your specific display panel you will have to
> +	  select the proper drivers which depend on this option.
> +
> +config DISPLAY_DDC
> +	tristate "Enable EDID parsing"
> +	---help---
> +	  Enable EDID parsing

"Enable" makes it sound like a boolean, not a tristate....

> +
> +comment "Display hardware drivers"
> +	depends on DISPLAY_SUPPORT
> +
> +endmenu
> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/Makefile fbdev-2.6/drivers/video/display/Makefile
> --- linus-2.6/drivers/video/display/Makefile	1969-12-31 19:00:00.000000000 -0500
> +++ fbdev-2.6/drivers/video/display/Makefile	2006-12-03 05:02:07.000000000 -0500
> @@ -0,0 +1,7 @@
> +# Display drivers
> +
> +display-objs				:= display-sysfs.o 
> +
> +obj-$(CONFIG_DISPLAY_SUPPORT)		+= display.o
> +
> +obj-$(CONFIG_DISPLAY_DDC)		+= display-ddc.o
> diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/Kconfig fbdev-2.6/drivers/video/Kconfig
> --- linus-2.6/drivers/video/Kconfig	2006-11-30 05:06:13.000000000 -0500
> +++ fbdev-2.6/drivers/video/Kconfig	2006-12-04 10:40:48.000000000 -0500
> @@ -4,21 +4,6 @@
>  
>  menu "Graphics support"
>  
> -config FIRMWARE_EDID
> -       bool "Enable firmware EDID"
> -       default y
> -       ---help---
> -         This enables access to the EDID transferred from the firmware.
> -	 On the i386, this is from the Video BIOS. Enable this if DDC/I2C
> -	 transfers do not work for your driver and if you are using
> -	 nvidiafb, i810fb or savagefb.
> -
> -	 In general, choosing Y for this option is safe.  If you
> -	 experience extremely long delays while booting before you get
> -	 something on your display, try setting this to N.  Matrox cards in
> -	 combination with certain motherboards and monitors are known to
> -	 suffer from this problem.
> -
>  config FB
>  	tristate "Support for frame buffer devices"
>  	---help---
> @@ -53,6 +38,22 @@
>  	  (e.g. an accelerated X server) and that are not frame buffer
>  	  device-aware may cause unexpected results. If unsure, say N.
>  
> +config FIRMWARE_EDID
> +       bool "Enable firmware EDID"
> +       depends on FB
> +       default n 
> +       ---help---
> +         This enables access to the EDID transferred from the firmware.
> +	 On the i386, this is from the Video BIOS. Enable this if DDC/I2C
> +	 transfers do not work for your driver and if you are using
> +	 nvidiafb, i810fb or savagefb.
> +

All of the help text (above & below) should be indented like the
first line above is:  one tab + 2 spaces.

> +	 In general, choosing Y for this option is safe.  If you
> +	 experience extremely long delays while booting before you get
> +	 something on your display, try setting this to N.  Matrox cards in
> +	 combination with certain motherboards and monitors are known to
> +	 suffer from this problem.
> +
>  config FB_DDC
>         tristate
>         depends on FB && I2C && I2C_ALGOBIT

---
~Randy

Display class

[James Simmons]

This is the pass at a display class to meet the needs of the output class 
of Mr. Yu for acpi. Also this class could in time replace the lcd class 
located in the backlight directory since a lcd is a type of display.
The final hope is that the purpose auxdisplay could fall under this 
catergory.

P.S
   I know the edid parsing would have to be pulled out of the fbdev layer.


diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/acpi/video.c fbdev-2.6/drivers/acpi/video.c
--- linus-2.6/drivers/acpi/video.c	2006-11-07 05:38:34.000000000 -0500
+++ fbdev-2.6/drivers/acpi/video.c	2006-12-04 10:40:48.000000000 -0500
@@ -30,6 +30,9 @@
 #include <linux/list.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#if defined(CONFIG_DISPLAY_DDC)
+#include <linux/display.h> 
+#endif
 
 #include <asm/uaccess.h>
 
@@ -154,6 +157,20 @@
 	int *levels;
 };
 
+#if defined(CONFIG_DISPLAY_DDC)
+static int
+acpi_display_get_power(struct display_device *dev)
+{
+	return 0;
+}
+
+static int
+acpi_display_set_power(struct display_device *dev)
+{
+	return 0;
+}
+#endif
+
 struct acpi_video_device {
 	unsigned long device_id;
 	struct acpi_video_device_flags flags;
@@ -162,6 +179,10 @@
 	struct acpi_video_bus *video;
 	struct acpi_device *dev;
 	struct acpi_video_device_brightness *brightness;
+#if defined(CONFIG_DISPLAY_DDC)
+	struct display_properties acpi_display_properties;
+	struct display_device *display;
+#endif
 };
 
 /* bus */
@@ -399,6 +420,27 @@
 	return status;
 }
 
+#if defined(CONFIG_DISPLAY_DDC)
+static void*
+acpi_display_get_EDID(struct acpi_video_device *dev)
+{
+	union acpi_object *edid = NULL;
+	void *data = NULL;
+	int status;
+
+	status = acpi_video_device_EDID(dev, &edid, 128);
+	if (ACPI_FAILURE(status))
+		status = acpi_video_device_EDID(dev, &edid, 256);
+
+	if (ACPI_SUCCESS(status)) {
+		if (edid && edid->type == ACPI_TYPE_BUFFER) {
+			data = edid->buffer.pointer;
+		}
+	}
+	return data;
+}
+#endif
+
 /* bus */
 
 static int
@@ -1255,7 +1297,6 @@
 	int status;
 	struct acpi_video_device *data;
 
-
 	if (!device || !video)
 		return -EINVAL;
 
@@ -1263,12 +1304,10 @@
 	    acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
 	if (ACPI_SUCCESS(status)) {
 
-		data = kmalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
+		data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
 		if (!data)
 			return -ENOMEM;
 
-		memset(data, 0, sizeof(struct acpi_video_device));
-
 		strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
 		strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
 		acpi_driver_data(device) = data;
@@ -1295,6 +1334,13 @@
 		acpi_video_device_bind(video, data);
 		acpi_video_device_find_cap(data);
 
+#ifdef CONFIG_DISPLAY_DDC
+		data->acpi_display_properties.get_power = acpi_display_get_power;
+		data->acpi_display_properties.set_power = acpi_display_set_power;
+		data->acpi_display_properties.probe = probe_edid;
+		data->display = display_device_register(NULL, acpi_display_get_EDID(data),
+							&data->acpi_display_properties);		
+#endif
 		status = acpi_install_notify_handler(device->handle,
 						     ACPI_DEVICE_NOTIFY,
 						     acpi_video_device_notify,
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/display-ddc.c fbdev-2.6/drivers/video/display/display-ddc.c
--- linus-2.6/drivers/video/display/display-ddc.c	1969-12-31 19:00:00.000000000 -0500
+++ fbdev-2.6/drivers/video/display/display-ddc.c	2006-12-03 05:27:00.000000000 -0500
@@ -0,0 +1,45 @@
+/*
+ *  display-ddc.c - EDID paring code
+ *
+ *  Copyright (C) 2006 James Simmons <jsimmons@infradead.org>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/module.h>
+#include <linux/display.h>
+#include <linux/err.h>
+#include <linux/ctype.h>
+
+#include <linux/fb.h>
+
+int probe_edid(struct display_device *dev, void *data)
+{
+	struct fb_monspecs spec;
+	ssize_t size = 45;
+
+	dev->name = kzalloc(size, GFP_KERNEL);
+	fb_edid_to_monspecs((unsigned char *) data, &spec);
+	strcpy(dev->name, spec.manufacturer);
+	return snprintf(dev->name, size, "%s %s %s\n", spec.manufacturer, spec.monitor, spec.ascii);
+}
+EXPORT_SYMBOL(probe_edid);
+
+MODULE_DESCRIPTION("Display Hardware handling");
+MODULE_AUTHOR("James Simmons <jsimmons@infradead.org>");
+MODULE_LICENSE("GPL");
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/display-sysfs.c fbdev-2.6/drivers/video/display/display-sysfs.c
--- linus-2.6/drivers/video/display/display-sysfs.c	1969-12-31 19:00:00.000000000 -0500
+++ fbdev-2.6/drivers/video/display/display-sysfs.c	2006-12-04 07:48:34.000000000 -0500
@@ -0,0 +1,164 @@
+/*
+ *  display.c - Display output driver
+ *
+ *  Copyright (C) 2006 James Simmons <jsimmons@infradead.org>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/module.h>
+#include <linux/display.h>
+#include <linux/err.h>
+#include <linux/ctype.h>
+
+static ssize_t display_show_name(struct class_device *dev, char *buf)
+{
+	struct display_device *dsp = to_display_device(dev);
+	return snprintf(buf, PAGE_SIZE, "%s\n", dsp->name);
+}
+
+static ssize_t display_show_power(struct class_device *dev, char *buf)
+{
+	struct display_device *dsp = to_display_device(dev);
+	ssize_t ret = -ENXIO;
+
+	mutex_lock(&dsp->lock);
+	if (likely(dsp->driver->get_power))
+		ret = sprintf(buf,"%.8x\n", dsp->driver->get_power(dsp));
+	mutex_unlock(&dsp->lock);
+	return ret;
+}
+
+static ssize_t display_store_power(struct class_device *dev,
+	const char *buf,size_t count)
+{
+	struct display_device *dsp = to_display_device(dev);
+	size_t size;
+	char *endp;
+	int power;
+
+	power = simple_strtoul(buf, &endp, 0);
+	size = endp - buf;
+	if (*endp && isspace(*endp))
+		size++;
+	if (size != count)
+		return -EINVAL;
+
+	mutex_lock(&dsp->lock);
+	if (likely(dsp->driver->set_power)) {
+		dsp->request_state = power;
+		dsp->driver->set_power(dsp);
+	}
+	mutex_unlock(&dsp->lock);
+	return count;
+}
+
+static void display_class_release(struct class_device *dev)
+{
+	struct display_device *dsp = to_display_device(dev);
+	kfree(dsp);
+}
+
+static struct class_device_attribute display_attributes[] = {
+	__ATTR(name, S_IRUGO, display_show_name, NULL),
+	__ATTR(power, S_IRUGO | S_IWUSR, display_show_power, display_store_power),
+};
+
+static struct class display_class = {
+	.name = "display",
+	.release = display_class_release,
+	.class_dev_attrs = display_attributes,
+};
+
+static int index;
+
+struct display_device *display_device_register(struct display_driver *driver,
+						struct device *dev, void *devdata)
+{
+	struct display_device *new_dev;
+	int ret = -ENOMEM, i;
+
+	if (unlikely(!driver))
+		return ERR_PTR(-EINVAL);
+
+	new_dev = kzalloc(sizeof(struct display_device), GFP_KERNEL);
+	if (likely(new_dev)) {
+		driver->probe(new_dev, devdata);
+
+		mutex_init(&new_dev->lock);
+		new_dev->driver = driver;
+		new_dev->class_dev.class = &display_class;
+		new_dev->class_dev.dev = dev;
+		sprintf(new_dev->class_dev.class_id, "display%d", index++);
+		class_set_devdata(&new_dev->class_dev, devdata);
+		ret = class_device_register(&new_dev->class_dev);
+
+		if (likely(ret)) {
+			for (i = 0; i < ARRAY_SIZE(display_attributes); i++) {
+				ret = class_device_create_file(&new_dev->class_dev,
+								&display_attributes[i]);
+				if (unlikely(ret)) {
+					while (--i >= 0)
+						class_device_remove_file(&new_dev->class_dev,
+								&display_attributes[i]);
+					class_device_unregister(&new_dev->class_dev);
+				}
+			}
+		}
+	}
+	if (unlikely(ret)) {
+		printk("failed to register display device\n");
+		kfree(new_dev);
+		new_dev = ERR_PTR(ret);
+	}
+	return new_dev;
+}
+EXPORT_SYMBOL(display_device_register);
+
+void display_device_unregister(struct display_device *dev)
+{
+	int i;
+
+	if (!dev)
+		return;
+	mutex_lock(&dev->lock);
+	dev->driver = NULL;
+	for (i = 0; i < ARRAY_SIZE(display_attributes); i++)
+		class_device_remove_file(&dev->class_dev,
+					&display_attributes[i]);
+	mutex_unlock(&dev->lock);
+	class_device_unregister(&dev->class_dev);
+}
+EXPORT_SYMBOL(display_device_unregister);
+
+static void __exit display_class_exit(void)
+{
+	class_unregister(&display_class);
+}
+
+static int __init display_class_init(void)
+{
+	return class_register(&display_class);
+}
+
+postcore_initcall(display_class_init);
+module_exit(display_class_exit);
+
+MODULE_DESCRIPTION("Display Hardware handling");
+MODULE_AUTHOR("James Simmons <jsimmons@infradead.org>");
+MODULE_LICENSE("GPL");
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/Kconfig fbdev-2.6/drivers/video/display/Kconfig
--- linus-2.6/drivers/video/display/Kconfig	1969-12-31 19:00:00.000000000 -0500
+++ fbdev-2.6/drivers/video/display/Kconfig	2006-12-04 11:41:03.000000000 -0500
@@ -0,0 +1,29 @@
+#
+# Display drivers configuration
+#
+
+menu "Display device support"
+
+config DISPLAY_SUPPORT
+	tristate "Display panel/monitor support"
+	---help---
+	  This framework adds support for low-level control of a display. 
+	  This includes support for power.
+
+	  Enable this to be able to choose the drivers for controlling the
+	  physical display panel/monitor on some platforms. This not only
+	  covers LCD displays for PDAs but also other types of displays
+	  such as CRT, TVout etc.
+
+	  To have support for your specific display panel you will have to
+	  select the proper drivers which depend on this option.
+
+config DISPLAY_DDC
+	tristate "Enable EDID parsing"
+	---help---
+	  Enable EDID parsing
+
+comment "Display hardware drivers"
+	depends on DISPLAY_SUPPORT
+
+endmenu
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/display/Makefile fbdev-2.6/drivers/video/display/Makefile
--- linus-2.6/drivers/video/display/Makefile	1969-12-31 19:00:00.000000000 -0500
+++ fbdev-2.6/drivers/video/display/Makefile	2006-12-03 05:02:07.000000000 -0500
@@ -0,0 +1,7 @@
+# Display drivers
+
+display-objs				:= display-sysfs.o 
+
+obj-$(CONFIG_DISPLAY_SUPPORT)		+= display.o
+
+obj-$(CONFIG_DISPLAY_DDC)		+= display-ddc.o
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/Kconfig fbdev-2.6/drivers/video/Kconfig
--- linus-2.6/drivers/video/Kconfig	2006-11-30 05:06:13.000000000 -0500
+++ fbdev-2.6/drivers/video/Kconfig	2006-12-04 10:40:48.000000000 -0500
@@ -4,21 +4,6 @@
 
 menu "Graphics support"
 
-config FIRMWARE_EDID
-       bool "Enable firmware EDID"
-       default y
-       ---help---
-         This enables access to the EDID transferred from the firmware.
-	 On the i386, this is from the Video BIOS. Enable this if DDC/I2C
-	 transfers do not work for your driver and if you are using
-	 nvidiafb, i810fb or savagefb.
-
-	 In general, choosing Y for this option is safe.  If you
-	 experience extremely long delays while booting before you get
-	 something on your display, try setting this to N.  Matrox cards in
-	 combination with certain motherboards and monitors are known to
-	 suffer from this problem.
-
 config FB
 	tristate "Support for frame buffer devices"
 	---help---
@@ -53,6 +38,22 @@
 	  (e.g. an accelerated X server) and that are not frame buffer
 	  device-aware may cause unexpected results. If unsure, say N.
 
+config FIRMWARE_EDID
+       bool "Enable firmware EDID"
+       depends on FB
+       default n 
+       ---help---
+         This enables access to the EDID transferred from the firmware.
+	 On the i386, this is from the Video BIOS. Enable this if DDC/I2C
+	 transfers do not work for your driver and if you are using
+	 nvidiafb, i810fb or savagefb.
+
+	 In general, choosing Y for this option is safe.  If you
+	 experience extremely long delays while booting before you get
+	 something on your display, try setting this to N.  Matrox cards in
+	 combination with certain motherboards and monitors are known to
+	 suffer from this problem.
+
 config FB_DDC
        tristate
        depends on FB && I2C && I2C_ALGOBIT
@@ -126,6 +127,9 @@
 	 This is particularly important to one driver, matroxfb.  If
 	 unsure, say N.
 
+comment "Frambuffer hardware drivers"
+	depends on FB
+
 config FB_CIRRUS
 	tristate "Cirrus Logic support"
 	depends on FB && (ZORRO || PCI)
@@ -1641,6 +1647,7 @@
 endif
 
 if SYSFS
+	source "drivers/video/display/Kconfig"
 	source "drivers/video/backlight/Kconfig"
 endif
 
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/drivers/video/Makefile fbdev-2.6/drivers/video/Makefile
--- linus-2.6/drivers/video/Makefile	2006-11-07 05:38:36.000000000 -0500
+++ fbdev-2.6/drivers/video/Makefile	2006-12-04 10:40:48.000000000 -0500
@@ -12,7 +12,7 @@
 
 obj-$(CONFIG_VT)		  += console/
 obj-$(CONFIG_LOGO)		  += logo/
-obj-$(CONFIG_SYSFS)		  += backlight/
+obj-$(CONFIG_SYSFS)		  += backlight/ display/
 
 obj-$(CONFIG_FB_CFB_FILLRECT)  += cfbfillrect.o
 obj-$(CONFIG_FB_CFB_COPYAREA)  += cfbcopyarea.o
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/include/linux/display.h fbdev-2.6/include/linux/display.h
--- linus-2.6/include/linux/display.h	1969-12-31 19:00:00.000000000 -0500
+++ fbdev-2.6/include/linux/display.h	2006-12-04 07:42:29.000000000 -0500
@@ -0,0 +1,55 @@
+/*
+ *  Copyright (C) 2006 James Simmons <jsimmons@infradead.org>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#ifndef _LINUX_DISPLAY_H
+#define _LINUX_DISPLAY_H
+
+#include <linux/device.h>
+
+struct display_device;
+
+/* This structure defines all the properties of a Display. */
+struct display_driver {
+	int (*set_power)(struct display_device *);
+	int (*get_power)(struct display_device *);
+	int (*probe)(struct display_device *, void *);
+	int (*remove)(struct display_device *);
+};
+
+struct display_device {
+	struct module *owner;	/* Owner module */
+	char *name;
+	struct mutex lock;	
+	int request_state;
+	struct display_driver *driver;
+	struct class_device class_dev;		/* The class device structure */
+};
+
+extern struct display_device *display_device_register(struct display_driver *driver,
+					struct device *dev, void *devdata);
+extern void display_device_unregister(struct display_device *dev);
+
+extern int probe_edid(struct display_device *dev, void *devdata);
+
+#define to_display_device(obj) container_of(obj, struct display_device, class_dev)
+
+#endif
diff -urN -X fbdev-2.6/Documentation/dontdiff linus-2.6/MAINTAINERS fbdev-2.6/MAINTAINERS
--- linus-2.6/MAINTAINERS	2006-12-04 04:11:38.000000000 -0500
+++ fbdev-2.6/MAINTAINERS	2006-12-04 10:40:48.000000000 -0500
@@ -911,6 +923,12 @@
 L:	linux-kernel@vger.kernel.org
 S:	Maintained
 
+DISPLAY SUBSYSTEM
+P:	James Simmons
+M:	jsimmons@infradead.org
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+
 DISTRIBUTED LOCK MANAGER
 P:	Patrick Caulfield
 M:	pcaulfie@redhat.com